There are two to start with. Feel free to suggest any others.

Any %: Finish the game as quickly as possible by any means.

Fire and Sword Total: Total completion time for all 10 "With Fire and Sword: Spiders" levels.

100% could be interesting. This game has a ton of collectibles and misc. tasks to complete

69 Patient Cards
4 Patient Recordings 
4 RC Cars (secret memory of Adam)
4 Roses (Find the final resting place)
10 Mini Games (Fire and Sword)
Voxel Runner (Trapware mini game hiscore 3,000)
Adam's Trapware (could just require all Dream Eater Sequences)

I would agree to having a 100% category. would make for an interesting run and routing would be a challenge that im sure would be enjoyable to figure out