Red Ball is one of the great browser platformers and its premise is almost aggressively simple: you are a red ball, the world is being turned square by boxes, and you roll right.

The physics carry it. Momentum matters, the ball squashes on impact, and levels are built around slopes, seesaws and things that need pushing rather than precise jumping. It's a platformer where you never quite have full control, and the small amount of slipperiness is the whole point.

The antagonists deserve credit for being one of the more memorable villain concepts in casual gaming - square, black, permanently frowning, and dedicated to converting all round things into cubes. It's a design so clean that it needs no explanation at all.

The series ran through Flash, then mobile, and kept its identity intact across both, which very few browser games managed.

This collection covers the ball and the boxes. Round versus square, permanently.