HTML5 Asteroids

Doug McInnes built HTML5 Asteroids in 2010, in the narrow window when "does this even work in a browser" was still a legitimate question for canvas games, and it answers that question well: this is Atari's 1979 vector shooter reproduced with real inertial physics, real screen-wrap, and real fragmenting asteroids, running in plain JavaScript with jQuery for event handling and no build step. Judged purely as a keyboard game, it holds up. Judged as a candidate for a shelf whose entire premise is that Flash games finally get to work on a phone, it fails on the one thing that matters most.

The keyboard build is exactly what it claims to be

Arrow keys rotate and thrust, space fires, and game.js implements the physics the way the arcade original did: your ship carries momentum through a turn rather than snapping to a new heading, bullets have a fixed lifetime rather than travelling forever, and a large asteroid splits into two smaller ones when it takes a hit, exactly as it should. Playing it through a playtest.js desktop pass — repeated ArrowUp and Space presses — spawns the ship, applies visible thrust, and fires a bullet that appears on screen and travels independently of the ship. None of this is a surprise for a 2010 reference implementation that has been forked 335 times, but it means the fundamentals are solid: this is a real Asteroids clone, not a tech demo with a score counter.

The touch layer does not survive contact with a real phone

ipad.js is a 34-line file, and its entire content — showing the four on-screen buttons, sizing the canvas for a tablet, and binding touchstart/touchmove/touchend to the same KEY_STATUS object the keyboard handler writes to — sits inside a single if (ipad) block, where ipad is set once at the top of the file:

var ipad = navigator.userAgent.match(/iPad/i) != null;

If that regex does not match, the buttons never get their display: block, never bind a touch listener, and the canvas never gets resized off its default 780x540. Running the game through playtest.js on the shelf's standard phone profile (390x844, real touch emulation via CDP) confirms exactly that: the canvas loads at its fixed desktop size in the corner of the viewport, PRESS SPACE TO START renders correctly, and tapping the exact screen positions where the thrust, turn, and fire buttons would sit — because they never appeared — does nothing. Only the keyboard steps in the same script moved the ship. Zero console errors were thrown; the code simply never attempted to run the touch path at all, because Chromium's default user agent, on a real Android phone or an iPhone or a simulated touch device, does not contain "iPad."

The deeper problem is that this check would fail on a growing share of real iPads too. Apple changed iPadOS's default browser identification to a desktop Safari string back in iPadOS 13, in 2019 — a year after this repository's last substantial gameplay change — specifically so sites would stop serving iPads a cut-down mobile layout. An iPad running a default, unmodified Safari install today reports itself as a Macintosh, not something matching /iPad/i. This is not a niche edge case; it means the on-screen controls this code was written for are now unreachable on the exact device family they targeted, in addition to every device they never supported at all.

This shelf exists specifically because Flash's death broke phone access to an entire generation of games, and the fix is supposed to be "these have real touch controls now." A game with touch handlers that never activate on almost any real touch device is a harder failure than a game with clumsy touch handlers — Space Huggers, rejected earlier for this shelf, at least let a thumb aim and shoot even though it couldn't move or jump. HTML5 Asteroids lets a thumb do nothing.

Where that leaves the score

There's no case for padding this. The physics and the presentation are honestly good — visuals and gameplay both land in the middle of the scale on their own terms — but originality is essentially absent for an intentionally unmodified clone, and controls, the category this shelf weighs hardest, has to reflect that touch input does not function for the audience the section exists to serve. A 4.0 sits it firmly at "some worthwhile ideas, but major weaknesses dominate": the ideas are Atari's from 1979, faithfully carried over, and the major weakness is that nobody holding a phone can actually play it.

GitHub shows 355 stars and 335 forks on the canonical repository as of this writing, with the last commit in April 2024 and five open issues sitting unaddressed — a widely reused reference implementation, but not an actively maintained one, and not one that would be improved by Dave's team fixing the user-agent check on its behalf.