Cashfall: Mental Math Arcade Active

Cashfall turns mental arithmetic into an arcade game. Coins and bills fall into a tray one after another, and you hold the running total in your head — because the stream stops without warning and asks what it came to. Answer fast enough and the streak multiplier climbs; miss by a cent and it resets.

Four levels build from counting change to a full register of bills and coins at speed, and an endless mode keeps raising the tempo until you lose your last life. Every round is generated from a seed, so difficulty comes from pace and denomination mix rather than from anything hidden.