Start values (lives, gold, map width) apply on restart. Everything else is live.
Upgrade Tower
Pick 1 of 3 cards · 50g each
Wave0
Lives20
Gold200
Length+0%
Switchback
Place towers to wind the path the creeps walk. Longer maze = more damage. Hold them off — wave by wave.
Pick 1 of 3 tower shapes at the bottom (20g per cell). The center cell fires — the others extend your maze. Towers gain XP from damage; click a glowing tower to draw a card.