Too repetitive. You always knew where to go, and the amount of clever puzzles was less. MP3 was a disaster zone though, so...
Visit three areas.
In each area, there are identical light and dark worlds, forcing you to play twice.
In each area, one finds three keys and then fights one big boss in the temple area. The temple area is always the same. After this, you return to the hub area to find the next area.
After you've done all three areas, you must search for nine keys: two in each area and three in the main area. You are told where to go for these too.
After this, you must enter the dark version of the hub area and go to the dark version of the main temple, and then fight the final boss in the predictable location of the central temple.
End.
The eight key areas are:
- Desert (brown)
- Dark desert (purple)
- Swamp (brown)
- Dark swamp (purple)
- Fortress (grey)
- Dark fortress (purple)
- Hub desert (brown)
- Dark hub desert (purple)
Brown, grey, purple. Over and over.
Metroid Prime 1, on the other hand, you didn't know where to go next and each area was very different.