Snake

Steer with the arrow keys, WASD or a swipe. Every apple makes you one segment longer, the walls kill and so does your own tail. Hold space to move faster: it costs you reaction time but never changes your score, because the board ranks apples first and then the number of cells you travelled to get them. Daily seed mode hands everyone the same apple sequence, so the run is a straight skill comparison. Each run is replayed server-side before it reaches the global leaderboard.