Alright, this is a pretty cool idea in theory.
First off, I loved the usage of slopes in the first act of Propulsion Canyon but I was stunned not only because of how taxing it is for my computer, but how incredibly SHORT it was. I saw a spring leading to what seemed like another part of the level and the level itself ended before i feel like it even had a chance to really start, I would really love to see this level design expanded upon.
I was really impressed by this act because seeing your screenshots in your editing thread. The gifs you showed off looked very barren so I didn't know what to expect and whatever it was it certainly was NOT this. Well done!
Secondly, I realised on my second playthrough that act 2 starts where act 1 left off, which is ok but made me feel like the two acts could've been split a bit differently. However, the level design feels a bit cryptic in this stage. The circular path around the cliff side at the beginning of the stage seems to indicate that you are supposed to get to the top of it to progress, and the path to the right has these mushrooms going off into the middle of nowhere with no discernable path outside of that, and then the rings over the pit just does not seem like a place I should be able to go. This act also seems much more closed off and flat than the previous act, with the item and ring placements being far more... sporadic. Your rings are often either spread too thinly, or bunched up too closely together, adding to the claustrophobic feel of the level.
Both acts are quite nicely populated with enemies and scenery, though I think to save on framerate you could thin out your usage of fish in the beginning of the first act. I would like to see a bit more going on visually in the cave system of the second act and maybe fix this:
The boss act is just a bit too cramped for my liking, making it incredibly easy to hit the boss as well as get hit, the obstacles are the major factor here. if the arena were just a bit more spread out I feel like it would be greatly improved. The music choice is pretty fitting for a boss fight so I don't have any gripes with that.
And that's about- oh wait, there's more..?
Desolate Factory act 1 was pretty decent as a first level, definitely not as nicely populated as Propulsion Canyon's was, but nice none the less. The use of slopes was... "interesting" to say the least. Some of the decoration ideas are a bit questionable in my eyes, like the decision to put these two giant patch of flowers in the shape of an arrow in the middle of the road near the end of the act, and I can't help but feel that even though this is supposed to be a desolate factory that it's a bit bland even for Techno Hill zone standards. I understand that making assets is hard and the vanilla toolset isn't as great for stuff like this, so I wouldn't have blamed you if you had ripped some graphics from another game to add some variety in the scenery or something.
Act 2 starts off a bit better, but in some cases has even more of a monotonous tone than act 1 and is more cramped feeling than Propulsion Canyon's act 2. The ideas implimented in the act are much more interesting than act 1's, but the pros are outweighed by the cons of the level design being too confusing, and the gaps in the goop created by the platforms that rise above it when you press the button. The laser section takes some timing to get down which is a big difficulty spike compared to the first few levels, and the crampedness does not help when the camera is constantly bumping into walls. The laser section in the next room has a couple of lasers where they're just barely too high to jump over at their highest and don't have a large enough range to give the player enough time to consistantly make it through, so I ended up having to damage boost just to get through them.
Act 3 is probably the worst visually designed level in the bunch so far, the entire room is simply given this one-note, white metal texture save for what I assume was supposed to be an elevator and the ceiling which has a giant patch of the LiteR flat in the middle. This seems to be the least-worked on of all the levels in the pack.
All in all, this pack really got my hopes up in the beginning that my expectations were going to be surpassed, but as the pack went on my worries had been confirmed into certainty.
I would highly suggest continuing to work on expanding and filling out Propulsion Canyon, as it seems like the most far along and it was the most fun to play. Play around with slopes and custom textures in the latter zone and give it more detail and flesh out the boss fights more. This pack has great potential but I feel like you dropped your work on the first act to work on the second and then the second to work on the third and so forth, this is an ok way to approach things working a little on each thing at a time but keep things within reach.
