Oxyd was originally marketed as shareware, with the somewhat unusual twist that users downloaded the whole game for free, but only the first 10 levels can be played without a codebook that had to be purchased separately from Dongleware. It takes to play the entire game to discover all its secrets. Combinations of these extra elements allow to produce an almost infinite number of different puzzles. There are switches and laser beams, destructible obstacles, pitfalls and useful items, quicksand pits, hostile creatures/robots. The ball bounces around and may be destroyed by hazards. This basic mechanic is further wrapped into layers of additional rules.

A level is completed as soon as there are no unrevealed blocks left. The objective is to touch two same-coloured blocks in succession, so that they stay revealed. The player controls a black marble that rolls around levels (best controlled with a mouse), which is used to touch blocks that reveal a circle of a certain colour. Oxyd is an action-puzzle game based around the core concept of a tile-matching puzzle, but with many additional features.

Download Oxyd