Levels and worlds

30 campaign levels in three worlds. Each has 4 to 5 fixed waves. Clear a level to open the next; remaining station lives determine its 1 to 3 stars. Human play duration has not yet been measured.

• Village and hills (levels 1-10) warm wood and brass. You learn the loop, your first wagons and the first bosses.
• Factory town (levels 11-20) steel grey. Saboteurs break your track; balloons need anti-air.
• Mountain and harbour (levels 21-30) cold slate blue. Every kind of enemy at once, and the final boss.

Endless

After level 10 you unlock Endless: one field and 100 waves that get tougher, with a boss every tenth wave. Two seeds determine the waves offline; a commitment is shown before the run and checked after it.

Difficulty comes from better choices

Levels get harder because enemies are tougher and there are more of them, never because the game reacts to how you build.