Drop bombs to blast through brittle walls and the creatures wandering between them — clear the level, then run before the cross-shaped blast catches you too.
Swipe up/down/left/right to walk through open cells. Tap anywhere to drop a bomb on your current cell — it explodes after about three seconds in a plus-shaped blast that reaches a few cells in each direction. The blast destroys brittle (brown) walls and kills any creature on those cells, but it also kills YOU if you're standing in it. Solid (gray) walls block the blast. Clear every creature on the level to advance — bombs become more powerful and creatures more numerous each level. Three lives total.
Plant before retreat. The instant you tap, the bomb is committed — the moment to plan was before the tap. Visualize the cross beforehand and know which direction you'll flee, ideally around a solid-wall corner that physically blocks the blast.
You cannot walk back over your own bomb. Once dropped, the cell is impassable to you until it detonates. If you place a bomb without a clear exit on at least two sides, you're committing to a route — make sure the route doesn't dead-end in a creature.
Brittle walls are double-edged. They drop points and reveal new paths, but they also create new corridors creatures can flow through. Open the map deliberately, not eagerly — the smaller your accessible area, the easier it is to predict creature paths.
Corner kills are the cleanest. A solid wall corner lets the blast hit the creature in one arm of the cross while protecting you with the perpendicular wall. Practice placing bombs so the kill cell is one corridor down, and your safe cell is one corridor over.