Gridlock Nine

Gridlock Nine is pure brain food. Each level hands you a grid and a flow of energy you have to route from source to sink by rotating tiles. It sounds simple, and the first dozen levels are, but it quietly ramps into genuinely tricky spatial puzzles.

There's no timer and no score multiplier pressure — just you and the grid. That makes it ideal for offline play, since you can set it down mid-puzzle and come back later with a clear head. We solved a few that had been bugging us only after sleeping on them.

The whole thing is clean black-and-white with a single accent colour, and that restraint keeps your focus where it belongs. Hundreds of hand-made levels, all playable without a connection.

What we liked

• Hundreds of hand-crafted levels
• Zero timers, pure logic
• Minimalist design that stays readable