4Stack #21 — answers & breakdown

Monday, August 3, 2026

The sixteen cards in this puzzle were: Pac-Man, Galaga, Donkey Kong, Space Invaders, Pitfall!, Asteroids, Centipede, Breakout, Sonic the Hedgehog, Street Fighter II, Chrono Trigger, EarthBound, Contra, Castlevania, Gradius, Frogger.

The four stacks

Arcade classics

Pac-Man, Galaga, Donkey Kong, Space Invaders

Atari-era hits

Pitfall!, Asteroids, Centipede, Breakout

16-bit icons

Sonic the Hedgehog, Street Fighter II, Chrono Trigger, EarthBound

Konami classics

Contra, Castlevania, Gradius, Frogger

Want to try it yourself? Play puzzle #21 — archive plays don't affect your streak. Or jump into today's puzzle.