At the start, Project A spawns, followed by a General GreGory. 3 more Project As will spawn one after another, then the boss, a Nimoy Bore, spawns. No more enemies apart from Ms. Sign will spawn after that.
Uber strat: (no rich cat needed)
Use reindeer (pudding), xmas present, sushi for double starting money up, and pumpcat and macho for freeze up.
Bottom row is rover Mk II, zamboney, seafarer, corrupted psychocat, EVA unit 01.
Rover can keep Gregory away long enough to pop out the Eva 01, save the cat cannon for the boss wave. Spawn mainly rover, zamboney and seafarer, adding psychocat and macho as cash allows.