Metroid Fusion (GBA) - Part 23: The Unnamed Feeling
After acquiring the Gravity Suit from Nightmare and stopping its rampage on Sector 5, Samus takes a breather of sorts and finds herself in an underwater portion of Sector 4. The best part of this area is that we don't have a boss to fight here. The music in underwater Sector 4 is among the best tunes in the game, as I imagine one will find themselves at ease listening to it. The only thing about this level is that some of the enemies here can be quite bothersome to deal with. Either Power Bomb your way through them or place well-aimed Missiles to eliminate them. Along the way, Samus also finds a Security Room that allows her to open the Level 4 hatches. Compared to what you've had to deal with earlier in this game, this portion of it should be pretty manageable overall.