Sentinels against the clock

Star Battle, played here as Sentinels. One sentinel per row, column and region. None may touch.

Against the clock

250 levels, climbing from easy to expert. Every board still has exactly one answer you can reason your way to - you just have less time to find it. Running out costs the level and nothing else.

Levels

Unlimited has the same boards with no clock on them, if a level is being stubborn.