A strategy game where your units must reach a certain objective (could be a set number of steps/a destination/ an item).

Units move automatically after the round starts.

You have to build a way for them to do so.

Each one of them responds differently to buildings/ other units.

Depending on how you build units might clash or not complete their objective.

4 Units - ★ ✿ ✣ ❆
8 Buildings - A B C D E F G H

A blocks ★ 

B  blocks✿

C blocks✣

D blocks❆

E blocks★ ✿

F blocks✣ ❆

Gblocks ✿✣

H blocks❆★ 

★ clashes ✣❆

✣ clashes❆✿

❆clashes✿

✿clashes ★ 

Each level would have a different layout and there would be certain amount of buildings one can use.

Lots of room for adding complexity.