It was discovered that cycles of moving platforms are triggered when the platforms are shown on the screen. The game is stretched to the size of its container window, and different resolutions will trigger the moving platforms at different spots.

The addition of the level-timer version, plus the fact that the game size is different across different websites and mobile devices, led to the decision that all resolutions are allowed when submitting a run, as long as the game and the speedrun/level timer are visible clearly on the screen.

The easiest way to change the game resolution, is to play on the level-timer version, and then change the size of the browser window. If you play on full-screen, the resolution will be that of your monitor.