An alien ocean trench
Planet Thalassa-6: a wrapping deep-sea trench of glowing coral, marine snow and light shafts from a surface you never see. The sonar strip up top reads the whole trench at a glance — learn to fly by it.
Four domes. Guard them all.
The colony's habitat domes stand on the trench floor, and the machines lay siege with cutting beams. Dome shields recharge if the attackers are driven off — but every wave hits harder, and once a shield breaks, hull damage is forever. Lose all four and the colony is lost.
A biomech bestiary
Everything down here is half creature, half machine: raider squids with bolted armor and cable tentacles, jelly-mines pulsing around a robot core, barracuda drones on attack runs, and worse things on later waves.
Powerups that sink
Dead machines drop spread shot, rapid fire, shields, EMP charges and extra lives — and every one of them sinks slowly toward the silt. Once buried, gone. Dive for it or lose it.
The Leviathan
Every 5th wave an armored serpent rises: radial bullet storms, aimed spreads, and a hide that shrugs off your EMP. Kill it and it always drops a life token. Which sinks. Naturally.
Honest retro craft
Real underwater momentum, additive-glow visuals and every sound effect synthesized by the game's own code — no asset packs, one hand-written C++ program, tiny download.
