Only the cats standing on the wall can shoot — and shooting makes them overheat. A cat that fires long enough jams, goes silent, and needs time to cool. So you are always deciding who holds the wall: drag a hot cat down to the spawn zone to cool, send a fresh one up, and drop two matching cats together to merge them into a stronger tier. Merging resets the heat, which makes it a rescue as well as an upgrade. The Mildews — a damp fungus horde — ...
Drag a cat onto a matching cat to merge them into the next tier. The merged cat starts completely cool. Drag a hot cat down to the spawn zone to cool it, and drag a cool one up to the wall to fire. You can also tap a cat to select it, then tap where it should go. Only cats on the wall shoot. The bar under each cat is its burn time — when it runs out the cat jams, stops firing and has to cool before it works again. Call a cat with the button at the bottom; gold comes from every Mildew you kill. Don't let them reach the gate. When the gate falls, the level is over. Esc pauses, M mutes.