Two players, one keyboard

Every number below is a count of documentation: the control text a developer or publisher wrote about their own game, as it sits in SlowDen’s game registry, plus what the publisher’s own public page says. It is not a count of behaviour.

No game in this article is described as broken, or as working. We cannot tell you that from where we are sitting, and it is worth saying why, because the reason is a trap other people will hit too. These games run inside a cross-origin frame, drawing to a WebGL canvas we cannot see into. Screen captures of that region come back solid black even when the game is running perfectly, and a script asking the host page how many canvases exist gets the answer zero, because the canvas is not in the host document. We learned that the expensive way. So when this article says a game “is documented as” something, that phrasing is doing real work, and it is the strongest claim the evidence supports.

Two other honest limits. The registry holds 200 games in our source, of which 120 are on the live site today — our deploys are a manual step and the source runs ahead. Every game named below is labelled live or staged. And this is one catalogue of partner games, not a survey of the web.

Of the 200 entries, 155 carry a documented control list and 45 carry none at all. Reading all 155, sixteen entries describe a second player. They split three ways:

Group A is the interesting one. Here it is in full, with each game credited to its studio. All are Playgama partner titles; none was made by SlowDen.

Five are live and linked above; the other four are in our source and are not on the site yet, so they are named without links rather than pointed at a page that would return a 404.

There is close to a standard here. Five of the nine document WASD for one player and the arrow keys for the other — a convention old enough to predate the browser as a games platform, and one that survives because it is the only way to give two people non-overlapping keys on a keyboard neither of them chose. Two more take the opposite route and reduce each player to a single key. That detail matters later.

If you were a player looking for something to play with the person next to you, you would open the 2 Player category. Here is what is actually in it.

On the live site the category holds 8 games, and 6 of the 8 are chess, checkers, backgammon or sudoku — turn-based board games, where “two player” means taking turns with one mouse or one finger, and where the second player is often the computer or an online opponent. 4 of the 8 carry no documented controls at all. Only Rolling Balls Sea Race is a simultaneous shared-keyboard game.

Meanwhile the nine games that genuinely need two people pressing keys at the same moment are scattered: 4 in block-and-sandbox, 2 in Sports, 1 in Racing, 1 in Funny, and 1 in 2 Player.

While reading all 155 control lists, nine of them stopped mid-sentence with an ellipsis. Their lengths: 250, 253, 253, 254, 254, 256, 257, 258 and 259 characters. The longest control list in the catalogue that is not cut runs to 507 characters, so this is not a site-wide limit — it is something that happened to those nine entries on their way in.

What the cut removes is never random, because text has an order. Developers write the desktop keys first, then the second player, then the mobile section. So the truncation lands on exactly the two things this article is about:

Three concrete examples, quoted from our own registry exactly as they end:

stickman-kombat-2d   … Player 2: IJKL + : (colon) (attack), " (quote)…
gt-cars-mega-ramps   … Player2 Arrow keys = move  N = NOS  L = reset car position  U =…
animal-evolution-simulator
                     … Mouse wheel - zoom in/out of the camera  Smartphone controls: Left…

The third one is the clearest. A player on a phone reaches the words “Smartphone controls:” and then the sentence stops.

So we went and looked at where the text came from. The publisher’s own public page for that game carries the whole thing, with no ellipsis anywhere: a Mobile section listing a left joystick to move, a jump button, an attack button, a swipe on the left side of the screen for the camera, and taps for buttons. The information was never missing. It exists, it is public, and our copy of it stops one word into the sentence that a phone player needs. The same is true of GT Cars Mega Ramps, whose publisher page carries a complete control description and a plain statement that its two-player mode is split-screen on one keyboard.

We have not seen the data payload in between, so we are not going to name a mechanism we did not observe. What is measured is this: the full text exists upstream, and the version we show is incomplete. That is our defect to fix, and the fix is on our list rather than in this paragraph pretending to be already done.

Earlier today we published an audit of touch support across this same catalogue, and it put these nine games in a group described as documenting no touch input. Tonight we checked that claim against a source we had not used: each game’s own public page on the publisher’s site.

One of the nine does document touch, and we were the ones losing it. Basket Random’s publisher page lists three controls, not two:

W: Jump and Throw (Player 1)
Up Arrow: Jump and Throw (Player 2)
Virtual Buttons: Jump and Throw (Mobile)

Our registry entry for the same game carries the first two and not the third. Nothing was truncated here — the text is short and ends cleanly. It is simply a shorter rewrite that dropped the mobile line.

We checked the remaining eight the same way, reading the controls section of each publisher page by hand. Eight of the nine document no touch path upstream either, so the finding holds for those, and the one that does not has been corrected here and in the earlier article’s record. Notably Soccer Random — the same studio, the same one-key-per-player design as Basket Random — carries no mobile line on its publisher page at all. We are not going to guess why two sibling games differ.

Say you decided to port a shared-keyboard game to touch. How much screen is there to work with? We measured the embed box on a live SlowDen game page — /games/basket-random/, one of the nine — at five viewport widths, using same-origin frames.

The box holds at roughly a fifth of the screen’s area across every phone width and roughly doubles on a tablet, which is what you would expect from a fixed aspect ratio inside a fixed page padding. We measured a different game page on a different run last time and got the same numbers to within a couple of pixels, which is how you know it is the template and not the game.

Now the useful part. WCAG 2.2 Success Criterion 2.5.8, Level AA, asks for pointer targets of at least 24 by 24 CSS pixels. A 166 by 207 half is nearly seven times that in each direction. So the question is never “is there room for a button”. It is how many buttons each player needs:

• One input per player — Basket Random and Soccer Random both give each player a single key that jumps, blocks and shoots. Each player’s half becomes one enormous tap zone. This is a small change, not a rewrite.
• Two or three inputs per player — still workable in a 166 by 207 half, if you are willing to design rather than decorate.
• Move, jump, sprint, interact, camera, plus a shop and an inventory — which is what four of the nine actually document. Two of those side by side on a phone is not a layout problem you can solve with a smaller button.

The pattern worth noticing: the games that would be easiest to port are the ones already closest to it. A one-button-per-player design is not a limitation to apologise for. It is the thing that makes two people on one phone a real possibility instead of a joke.

Here is the live page for Basket Random today, quoted exactly. It opens with:

Play Basket Random free online on SlowDen — no download, no sign-up.
Press play and enjoy this Sports browser game instantly.

Then, under “How to play”:

2. Click or tap inside the game window to start.
3. Follow the in-game prompts — controls are listed below.

Controls
• Player 1: W   Player 2: UP ARROW

So the page tells a visitor to tap, and then tells them the game needs two people at a keyboard. Across the five live pages in group A, the word “touch” and the words “swipe”, “joystick” and “on-screen” appear zero times, on any of them. The word “instantly” appears four times in each page’s HTML.

That is our template, on our site, and it is the least flattering paragraph in this article, which is the main reason it is here. The replacement is written and sitting in our source, unshipped, because our deploys are manual and the site is frozen this month. It reads:

⌨ Two players, one keyboard

Built for a keyboard — and for two people at one. Basket Random is
documented as two players sharing a single keyboard, so it is made for
a computer rather than one phone. No touch alternative is listed.
That is what its control list says, not a test result.

We are not claiming credit for a fix a visitor cannot see yet. As of the time this was published, the live page still reads the way it is quoted above.

In rough order of how much they return for the effort.

1. Write the device answer first in your controls text. Not last. Every downstream system that reformats, shortens or truncates your description cuts from the end, and we have nine measured examples where the end was the mobile section or the second player. A first line reading “Two players, one keyboard — desktop only” survives everything.
2. If your game has one action per player, ship touch. You are one pair of tap zones away. Split the canvas down the middle, treat a tap on either half as that player’s key, and leave the keyboard bindings in place for desktop. It is the single cheapest way to turn a desktop-only game into one that works on the device half your visitors are holding.
3. Say when two-player is desktop-only, on the page, in words. One game in our catalogue does this and it is the best-documented entry we found: “On Mobile Devices: Only 1 Player mode is enabled on mobile devices. Tap left and right on the screen to move.” (Snow Rush 3D, by gameVgames — in our source, not yet on the live site.) A player who reads that is never disappointed. Compare it to a page that just says “tap to start”.
4. Make single-player complete on touch, and let co-op be the extra. This is the version of the trade that costs you nothing. The mistake is not building shared-keyboard co-op — it is building it as the only way in.
5. Document desktop and mobile as two separate lists, not one blended paragraph. The clearest entry in our whole catalogue does exactly that: Master Chess (CodeThisLab) lists click a piece / click a square for desktop and tap a piece / tap a square for mobile, as four separate lines. It takes thirty seconds to write and it answers the only question a phone player has.
6. Do not rely on a category to communicate your input model. Genre and device are different axes, and portals mostly only have the genre one. Put it in your own text, where it travels with the game.

• All figures measured on 5 August 2026, in Chrome on Windows.
• The catalogue audit reads the game registry directly. 200 entries in source, 120 live; 155 with a control list, 45 without.
• The regex used to find candidate entries produced one false positive, which is worth naming because it is the kind that looks like a finding: the pattern friend matched the ordinary phrase “user-friendly” and pulled in an entry that mentions no second player at all. Every one of the sixteen was read by hand before it was counted, and the hand count is what is published.
• Publisher pages were read directly for the nine group-A games plus two of the truncated entries. Only the controls section of each was used.
• Geometry was measured on a live page in same-origin frames at five viewport sizes. These are layout measurements at phone widths, not tests on phone hardware — the machine reports zero touch points, so no claim here is based on a real touch device.
• The accessibility figure is from the W3C recommendation, read this run. No other platform guideline is quoted, because the two we tried to verify would not render their own text to a fetch, and an unverified number is worse than a missing one.
• What this cannot tell you: whether any specific game plays well, or at all, with two people or one, on any device. Documentation is not behaviour. Nothing here is a review.

SlowDen lists browser games and takes submissions from developers. If you have a playable web build you can send it to us — and if two people need to share a keyboard for it, say so, because we would rather put that on the page than let someone find out on a bus.

Slow Cook is our creative challenge for developers: pick a challenge, build a small game around it, and submit it before the round closes on 31 August 2026. Selected entries may receive a shoutout on SlowDen’s social accounts and a chance to be featured — nothing is guaranteed, and every entry is read by a person.

Submit your game See the Slow Cook round

• Why your browser game is unplayable on a phone — this morning’s wider audit of touch support across the same catalogue, and the article corrected above.
• Why your browser game loads to a black screen — what a page does to a game before anyone presses anything.
• Which browser-game portals actually have players on them — where to list once the game survives first contact.
• Free browser games you can play right now — the player-side version, including several of the games above.
• How to submit your browser game to SlowDen.