BOMBANANA! Campaign — 30 Levels Explained

Campaign is 30 handcrafted levels, confirmed in Lefto Studio's launch announcement: "Campaign: 30 handcrafted levels which get progressively more difficult."
Handcrafted matters here. Unlike Endless, these are designed layouts — the module combinations on each level were chosen, not rolled. That is why the difficulty curve is a curve rather than a staircase.
How the difficulty works
The game introduces module types over time rather than dropping all eighteen on you at level one. Early levels give you one or two familiar modules with a generous timer. Later ones stack unfamiliar modules together and add environmental hazards on top.
The three campaign achievements — Junior Defuser, Expert Defuser, Master Defuser — suggest three progress milestones across the run, though Steam does not publish the thresholds.
When you stall
Players most commonly report stalling around level 5 and level 7.
Three things that help more than trying harder:
Drop into Custom mode. You can set which module types appear. If level 7 keeps killing you on one module, build a custom bomb with only that module and a long timer, and run it until the lookup is fast.
Swap roles. A group that has stalled has usually developed a communication blind spot. Rotating seats surfaces it in one round.
Leave a module and come back. Strikes are finite but so is time. Two failed attempts on the same module usually means the description was wrong, not the answer.
To be confirmed: which modules appear on which specific level, and the exact strike limit in campaign. We have not been able to confirm either from a source we trust, and a wrong answer here wastes the time of someone who is already stuck.