Bio-Base is the penultimate stage from Thunder Force IV.
Details[]
This stage takes place inside of the main base of operations of Vios, in the core of the Vios planet. This stage is relatively long, with many defenses around which shoot the player once it passes through a targeting laser and gear-like mechanisms which block the path or attempt to trap the player. Close to the end the player goes through a small area with lots of spores flying at the player, followed by a corridor with enemies coming from behind.
| Thunder Force IV | ||
| Characters | Roy S. Mercury • Carol T. Mars | |
| Ships | Fire LEO-04 "Rynex" | |
| Stages | Strite • Daser • Air Raid • Ruin • Vios • Volbados • Desvio • Wall • Bio-Base • Versus | |
| Bosses | Gargoyle Diver • Fomalhaut • Ratt Carry • Hell Arm • Versus • Spark Lancer • Dust Egg • Evil Core • Armament Claw • Faust | |