Fourfall: Four in a Row with a Gravity Flip

Four-in-a-row strategy with one dangerous extra move: once per game you may flip gravity and slide every column to the other side. Three AI opponents that use the flip too, or two players on one screen. Free, no ads, no tracking; keyboard or touch.

Fourfall is the classic line-up-four game with one dangerous extra move. Once per game, instead of dropping a disc, you may flip gravity: every column slides to the far end of the board in its own order, and stacks of different heights shift against each other.

A good flip makes a line out of nothing. A careless one can complete your opponent's line, and then they win the game. The AI opponents search the flip like any other move, so they will use it against you.

• The gravity flip: one per player per game; each column keeps its order and slides as a block
• Three AI opponents: Pebble (easy), Brook (looks four moves ahead) and Torrent (deep alpha-beta search with a time limit)
• Two players: Ember and Frost share one screen, keyboard or touch
• Matches: first to three games, the starting player alternates
• Points: 1 to 3 per game won by opponent strength, doubled for a win in 15 moves or fewer, plus a match bonus
• Readable discs: each colour also carries its own mark, and the last disc is outlined

Code and text written with AI assistance; checked by PN Scripts with automated tests. Every shape is drawn and every sound synthesised by code; there are no AI-generated image or audio files.

Controls

• ← → (or A / D): choose a column, Enter / Space / ↓: drop a disc
• 1-7: drop in that column
• F twice: flip gravity (once per game)
• Tap a column to drop; tap the Flip button twice to flip
• Opponent screen: ← → and Enter, 1-4, or tap a card
• P / Esc: pause, M: sound

Made by PN Scripts.