There's a percentage for all items you pick up and a percentage for how many things you have scanned. Combine these into 1 percentage.
Worst ending: 0-74%
Bad ending: 75-99%
Best ending: 100%
Beat the game once to unlock Hard Mode
There are 4 image galleries.
Image gallery 1: 50% of Scans
Image gallery 2: 100% of Scans
Image gallery 3: 50% Item Pickups
Image gallery 3: 100% Item Pickups
To play the original NES Metroid on your GameCube, beat Metroid Fusion. Now link your GameBoy Advance to your GameCube and go to the Load Screen. Select Fusion Connection Bonuses and follow the instructions for NES Metroid.
To get the Fusion suit in Metriod Prime, beat Metroid Prime after you beat Fusion and link up. Go to the Load Screen. Once your GBA is loaded, you can Claim Samus' Fusion suit in Prime.