ColorAttack

Color Attack is a color-matching puzzle. Monsters march down the board. You place turrets, paint a path, and stop them before they reach the danger line.

Each turn you drag a colored turret onto a painted tile. It paints ahead and fires only at monsters of the same color. Monsters move first, shots are limited, and a turret left in their path gets crushed. Clear the board, or the level ends.

Later levels ask for a real plan:

Stacked monsters hide a new color under the one you see.
Keys open locked gates.
Paint bombs splash color onto empty tiles, giving you new places to build.
Arrow tiles bend a shot so the rest of the ammo keeps going.
Some levels are split into regions. Clear one, then hold the next.
One hundred levels, with undo if a placement goes wrong. Match the color, spend every shot, and hold the line.