Heh, it's been a long couple of years since I've posted here, despite coming to lurk every once in a while. This particular level has caught my attention, especially considering you say it is your first. Sure you don't have any experience?
Anyways, on to the real reason I came out of my cave: expressing my opinion of this level. As with most occasions, I have broken down into categories of what i saw in the level.
Scenery
Well, as the title implies, it definitely gives off almost an angelic vibe. Even in the sewer, it still looks very nice. I do however wish that some areas were better lighted, so that I could see what I'm landing on/walking across. 8/10.
Gameplay
For intents of discovering the level's rough patches, I played as Dr.P's Sally (my view is that if you can get through it with her average speed and abilityless jump, that should give an idea of any really rough spots). As Sally, I was able to clear the level with relative ease, only messing up in the room with the drain vavle, seeing as how she doesn't have much ability to correct for jumping too far. This level actually wasn't in need of many enemies. Difficulty and length could have been a lot better.
7/10
Level Design in General
This catergory is just simply stuff I noticed that could be fixed, or that I'm just curious about.
-Did you intentionally make the tops of the rising walls a different texture, or was your original plan to make them blend into the floor until they popped up?
-In the underwater area, does that four-pillar structure do anything, because it almost looked like a warp.
-That tower near the green carpeted area looked cool, it was just a shame you wouldn't let me jump out to it. :(
-In close to the same area, your collapsing bridge doesn't have a bottomless pit tag under it, which got me stuck down there. May I suggest either lowering the bridge, adding a spring, or making it a true bottomless pit?
7/10
Final Score: 8/10
If anyone added up and averaged the scores, they probably noticed I rounded up...somewhat. This level definietly gets props for being a good first time, compiled with the fact that it has plenty of potential. Just maybe tweak difficulty and length, and a couple other things, and your bound to have a winner here.