Like:
Individual Levels!
Any% (finishing everything with at least 1 star)
Finish Level 6-5

@Chew can help because she did speedrun.com/squarecells
and basically this game should be like that

My god, I just saw your messages, sorry >.<
I'll look through the next few days for more categories!
Again, sorry for the very very very late answer :(

Finally, after a year (really sorry, I thought I did that...), all levels are there. I hope I did that well... 
Have fun if you still run the game :3