Planetoid C-4 is unlocked after obtaining Planetoid Map C-4 on Planetoid E-2. Planetoid C-4 is the sixth top-down planetoid; it consists of five rooms. The first room features three different pathways for the player to take; right, down, and up.
Going down will lead to a dead end.
Going right will lead to a room with Cables and various mutants, as well as a way down. Making it all the way down will lead to a room to the left. Going to the left will lead to the room below the starting area, albeit now the player can obtain the SP Up and activate the Retry Point. Additionally, there is a crack in the wall the player can break as a shortcut back to the starting room.
Going up leads to a room with breakable rocks, some of which contain Capsules, with another room above it. Continuing up leads to a lockdown segment, with Cables segregating parts of the arena. Beating this lockdown segment gives access to the Flash Striker Sub-weapon.
- Spread Sentry
- Blue GX680
- Blue Pyramid Turret
- Purple GX680
- Cross Cannon
- Red Pyramid Turret