Your health will keep decreasing, so keep hitting enemies to get additional health packs. Destroy things that regenerate enemies, specially the scorpions and purple sludges. Run away from the purple sludges while you shoot the Boss Core. Keep at least one regenerator so the Boss cannot summon more of them. If you have a bomb, use it while having the homing/spread weapon equipped. Stay away from enemies, and keep a high-level weapon at all times.
Blaster Master: Overdrive