Black Hole Square is a minimalist puzzle game made for the js13k 2021 contest, where the whole entry had to fit in 13 kilobytes. Each puzzle is a 6x6 board holding a few white tiles and black holes. Your job is to clean up the board so that no square is left, using only a fixed number of taps. There are no instructions beyond a welcome screen, so much of the fun is working out what each tile does.
How to Play Black Hole Square
Swipe left on the title and welcome screens to reach the first puzzle. The puzzle name sits in the top left, and the number of moves you have left sits in the top right.
Arrow tiles are the engine of the game. Tap one and it pushes itself and every square lined up in front of it one step in its direction. If the line reaches an empty cell, everything shifts over. If it reaches a black hole, the front square falls in and disappears. If it runs into the board edge, nothing moves.
Plain white tiles cannot be tapped and only move when pushed. Tiles marked with an X vanish when tapped. A tile with a gray square in its center is a neutron star, and tapping it turns it into a new black hole. The board is clean when only black holes remain, and you then move on to the next puzzle. Running out of moves, getting stuck or leaving only plain squares resets the puzzle.
Black Hole Square Controls
| Action | Mouse | Touch |
|---|---|---|
| Tap a tile (push a row, pop an X, or collapse a star) | Click the tile | Tap the tile |
| Skip to the next screen | Drag left across the board, or scroll sideways on a trackpad | Swipe left |
| Reset the puzzle (or go back if no moves were made) | Drag right across the board, or scroll sideways on a trackpad | Swipe right |
| Jump to any puzzle | Click a square in the progress row under the board | Tap a square in the progress row under the board |
Tips and Strategies
- Count the moves first. The limit is tight. The first puzzle gives you exactly the four taps it needs, so every tap should send something into a hole or set one up.
- Let one push do double work. An arrow shoves every tile lined up in front of it, so build a line before you push and several tiles can reach a hole in fewer taps.
- Keep plain tiles in line with an arrow. A plain white tile can only leave the board when an arrow pushes it, so never strand one off every arrow’s path.
- Use neutron stars as new targets. Collapsing one creates a black hole right where a row may be headed.
- Push X tiles instead of tapping them. X tiles can also be shoved into a hole, and that costs nothing extra if an arrow is already moving the row.
Features
- 18 hand-made puzzles, each named, from a one-idea opener to a 20-move finale.
- Several tile types: arrows in four directions, X tiles, neutron stars and plain tiles.
- Saved progress: your current puzzle and solved puzzles are kept in your browser.
- Generated sound: short tones for taps, wins and failures, all made in code.
Tested and updated:
