How to play
Aim across the top of the fusion chamber and drop a nucleus. When two nuclei of the same element touch they fuse into the next element up the alpha-process chain and score points — and one fusion can trigger the next, so a well-placed drop can cascade.
Every nucleus carries its element symbol as well as its colour and size, so neighbouring steps of the chain stay readable. Only the lightest few elements are ever fed in; everything heavier has to be built.
You lose when a nucleus comes to rest above the dashed red line and stays there — brushing past it on the way down is fine.
Fusion stops paying at iron, so iron cannot fuse upward. Two iron nuclei meeting collapse instead: a supernova, worth a 100-point bonus, and the only way to clear iron out of the chamber.
Move the pointer across the board or use ←/→ (or A/D) to aim, then click or press Space to drop. N starts a new game. Fusing charges the energy meter; spend it on the powers under the board, where Esc cancels one you have armed.