factorSMASH

Aim & fire: pick a number (2–13) below the launcher, drag anywhere (or arrow left, arrow right) to aim, then fire (space) — hit a target with one of its factors to divide it.

Smash targets: reduce a target all the way to a prime number to clear it for a bonus. Non-factor hits cost you points.

Watch the colours: targets turn blue → orange → red, then shake and drop and will hit your shields and you. Reduce them before they fall!

Shields: Three shield lines block small numbers 20 and under, then 10 and under, and the final shield 5 and under, but bigger falling numbers damage them. 4 hits and the shield breaks, then smaller numbers can get through.

Launcher: It has 3 lives. Once the shields are gone. Falling numbers will hit the launcher. Lose all 3, and it's game over.