70 levels into the set of 151, here are some levels I'd like to nominate.
Temple of No Key -- A bit difficult and exacting, but interesting challenges.
Vanity -- Medium difficulty block puzzles. Ending takes a while but isn't really too bad.
The Trouble with Mirrors -- A puzzle I remember enjoying from CCLP4 voting.
Grudge -- Maybe a surprising pick, but I liked the compact monster manipulation/dodging challenges and felt the level's short length really made it work without being frustrating.
Waterways -- A level that could be technically called guesswork when it comes to pushing on blue walls while dodging monsters, but in practice the path is visually indicated so intuitively that it's a smooth and fun solving experience. This is the sort of blue wall level I really like.
Blockage -- Some nice puzzles about figuring out how to make the best use of blocks that appear useless on first glance. I do think it needs more time, though; I ran out near the end on an attempt where I wasted very little.
Imperial Elevator -- A nice casual chips-under-blocks level that has just enough "hmm" moments near the end to be fun.
Florid Outlands -- Simple maze with nice aesthetics that requires just a bit of planning to get through certain parts.
Anomalous Materials -- I liked the aesthetics and it had a nice progression with puzzles that got harder but could be done in any order.
Here are some levels that I'll nominate because I enjoyed them even though they might not be as good as the ones above for various reasons:
Catalyst -- A neat concept, though admittedly I wish more was done with it or there was more of a puzzle surrounding it.
Pearl Harbour -- Yes, it's long, but it's fun to progressively unravel the blocks!
Dark Night -- A simple idea made a bit more exciting by the low time limit.
Hear Them Calling -- A strange one, but the timing was challenging at points without being ridiculous, and navigating through the outside to get back to the exit was kinda neat.
Dirty Love -- I really liked the sense of progression through the columns and creating partial posts behind you to get to the next column. It's held back a bit by the fact that you're never told not to teleport down, which can make things confusing if you do, and there are some places where you have to know what's coming up next to get through correctly (like the toggle wall and especially the glider trap). It is possible to preview, but can be easily missed.
Spirit in the Sky -- Simple dodging gameplay for the most part, but I just liked how it was laid out.
And two honorable mention, which I am NOT nominating but strongly considered:
Lithium-Ionized -- I enjoyed the aesthetics and the odd way of navigating around, and using blocks to open up a path back...but just wish it did something more varied with the 4 sections.
Crusher Castle -- This is a bit like Green Wrangler but with blocks instead of helmets to contain the monsters. I think both blobs and Teeth work well for a level of this kind, but the walker does not. (Too unpredictable and fast to chase down and trap; can hit you head-on before you can react if you're moving quickly.) Also I think there were a tad too many monsters and a little too much space. Basically I enjoyed most of it, but it wore out its welcome while I was dealing with the last two blobs.
Temple of No Key -- A bit difficult and exacting, but interesting challenges.
Vanity -- Medium difficulty block puzzles. Ending takes a while but isn't really too bad.
The Trouble with Mirrors -- A puzzle I remember enjoying from CCLP4 voting.
Grudge -- Maybe a surprising pick, but I liked the compact monster manipulation/dodging challenges and felt the level's short length really made it work without being frustrating.
Waterways -- A level that could be technically called guesswork when it comes to pushing on blue walls while dodging monsters, but in practice the path is visually indicated so intuitively that it's a smooth and fun solving experience. This is the sort of blue wall level I really like.
Blockage -- Some nice puzzles about figuring out how to make the best use of blocks that appear useless on first glance. I do think it needs more time, though; I ran out near the end on an attempt where I wasted very little.
Imperial Elevator -- A nice casual chips-under-blocks level that has just enough "hmm" moments near the end to be fun.
Florid Outlands -- Simple maze with nice aesthetics that requires just a bit of planning to get through certain parts.
Anomalous Materials -- I liked the aesthetics and it had a nice progression with puzzles that got harder but could be done in any order.
Here are some levels that I'll nominate because I enjoyed them even though they might not be as good as the ones above for various reasons:
Catalyst -- A neat concept, though admittedly I wish more was done with it or there was more of a puzzle surrounding it.
Pearl Harbour -- Yes, it's long, but it's fun to progressively unravel the blocks!
Dark Night -- A simple idea made a bit more exciting by the low time limit.
Hear Them Calling -- A strange one, but the timing was challenging at points without being ridiculous, and navigating through the outside to get back to the exit was kinda neat.
Dirty Love -- I really liked the sense of progression through the columns and creating partial posts behind you to get to the next column. It's held back a bit by the fact that you're never told not to teleport down, which can make things confusing if you do, and there are some places where you have to know what's coming up next to get through correctly (like the toggle wall and especially the glider trap). It is possible to preview, but can be easily missed.
Spirit in the Sky -- Simple dodging gameplay for the most part, but I just liked how it was laid out.
And two honorable mention, which I am NOT nominating but strongly considered:
Lithium-Ionized -- I enjoyed the aesthetics and the odd way of navigating around, and using blocks to open up a path back...but just wish it did something more varied with the 4 sections.
Crusher Castle -- This is a bit like Green Wrangler but with blocks instead of helmets to contain the monsters. I think both blobs and Teeth work well for a level of this kind, but the walker does not. (Too unpredictable and fast to chase down and trap; can hit you head-on before you can react if you're moving quickly.) Also I think there were a tad too many monsters and a little too much space. Basically I enjoyed most of it, but it wore out its welcome while I was dealing with the last two blobs.