Ramps differ by game
Heist tightens aim windows, Quest adds nastier decks, Build sends bigger waves. Each ramps its own way at its own pace, so no single trick solves all.
The boss database shows the late threats, and the character database shows who you field against them when the heat rises.
Economy is the gate
Most walls are resource walls. Fix the income before throwing more force at the problem you created by starving the town of its workers and coin.
Learn the pattern
Bosses and waves telegraph. The tell that kills you once is the tell to plan around the next time, so death becomes a lesson instead of a reset.
Come back stronger
If a stretch stalls, rebuild the economy and return. A stronger base clears what a brave one could not on the first run you threw at it.
Know when to pause
Push too far and the game punishes you. Step back, shore up the town, then advance with the surplus that turns a wall into a manageable step.