Alright, here's some criticism... though you may not like what I have to say:
I'm sorry man, but your level has a few issues that drag it down. Your main idea for challenges seems to be putting invisible traps everywhere (spikes and random no-jump/sticky/no-climb objects that you can't notice until it's too late... and even "fake" save points that force you to restart the level if you use them), and that really doesn't make for a fun and enjoyable experience. Some of the challenges are just trial-and-error fests, and that's just unfair and frustrating. There are some places where you can't even tell if the walls are solid or not. Trust me, there are a lot of better ways to make a hard challenge.
I also found a few wall-swims and void screens:
x1007y991: If you double-jump to the left, you'll fall through the void screens and get stuck on top of the spike traps at x1006y993. This is probably the same bug that Willster reported.
x1005y1001: The teleport takes you into the floor of the first area (wall-swim)
Also:
The "Win" object is placed in a empty tunnel that looks like a dead-end. The level ends abruptly. There should be at least a visible object (teleporter, ball of light, etc) at the end of that tunnel. Also, the word "congratulations" is misspelled in the ending screen
Oh and... this is just my personal opinion, but I think ambience track #22 does not fit that final area
at all.
On the plus side, graphics are nice. I liked the custom tilesets you made. Also, not all the challenges were trial-and-error... there were parts of the level that I did enjoy. I wouldn't say this is a bad level, but it could be much better if there weren't so many random invisible traps.
Sorry if I sounded harsh, but this was my honest opinion. I hope you find it useful for improving this level or for any future projects.