Conclusion: The linearity of Rochard makes it less conducive to repeated play-throughs. You can load up select missions to find any collectibles you may have missed, but only the trophy-obsessed are going to want to replay the same puzzles again. There are light RPG elements in that you can find upgrades to your weapons and for your health, but there is no external effect.
Pros: Non-space marine protagonist, gravity puzzles work well.
Cons: The southern theme never quite meshes, doesn't fully explore gameplay possibilities.