Side-scrolling platform games — the run-and-jump classics — are the genre most firmly closed to switch and eye-gaze players, and it is worth being specific about why. Running is a held key, and a switch is a press rather than a hold. Jumps are timed against hazards that are moving while you decide. And missing sends you back to the start of the level. Put those together and a player whose press arrives through a scanning cycle has not been asked to play badly — they have been asked to do something the equipment cannot do.

Acorn Hill is built the other way round. The hill only moves when you do: one press is one step or one hop, and the little beetles take exactly one step for each one Hazel the squirrel takes. That single decision removes reaction speed from the game entirely — you can take ten seconds over a press, or ten minutes, and find the hill exactly as you left it.

The hop is a fixed arc rather than a physics simulation, so the same press always does the same thing — which means the game can show you where you will land before you commit. A ring marks the landing tile. Nobody has to learn a jump by missing it a hundred times, which is exactly the practice an ordinary platformer assumes and a scanning player never gets. Hops also land on the first surface under the arc rather than always flying their full length, so the fiddly part — the precise landing — is the game's job, not yours.

Nothing here can be lost. Falling down a gap is a gust of wind putting Hazel back on the last safe ledge. Walking into a Grump is a bump backwards and a grumble. Neither takes an acorn away, neither restarts the hill, and there are no lives to run out of. Hopping on top of a Grump does not squash it either — it curls up for a nap and becomes a step you can stand on, permanently.

Everything is reachable from three big buttons: left, right, and hop. There is deliberately no separate “use” or “down” control — a pipe is taken by standing on it and a prize block is opened by hopping underneath it — because every extra control is another full stop on every scan sweep, on a hill that takes a couple of hundred presses. Long runs makes one press walk further, and stops itself the moment anything is worth a decision: an acorn, a beetle, a prize block overhead, or the edge of a drop.

There are four hills — Sunny Slope, The Brick Yard, Cloud Steps and The Long Climb — and they get longer and more vertical without ever getting faster. Acorns are optional: the flag finishes a hill however many you found. Progress saves itself on the device, hill by hill, and any hill you have reached can be replayed from the Acorns panel, which is a therapy need as much as a game one — the first hill is the one that teaches the three presses.

Play with the on-screen buttons, the arrow keys, or WASD; Space hops too. Switch scanning, eye-gaze dwell, button size, colour themes and spoken feedback all live in the app's Settings panel and can be saved per player.