SPOILERS</B>
If you acquire all 100% of the items in the game, you unlock a short secret ending in which Samus flies off to wherever and a blue ship follows her. At first I was thinking that it’s still Dark Samus because it just gave me that feeling, due to the Phazon-look of the ship. Retro has claimed that this is the last game in the trilogy, but this is certainly a cliffhanger. Do you think/want another game in the Prime series? Would you want the next Metroid game to take a different route?