First off, maybe this is normal for maps that are released in the editing section, but trying to start a new game with this wad loaded crashed SRB2 for me. I was able to play the act by going into Multiplayer.
Secondly, I guess I won't comment on the colors much now, since you say some of them are bugged, but yeah, the color scheme is very ugly as it currently stands.
This map feels a bit wrong to me. Overall, it's very simplistic and can be beaten in under 50 seconds by a non-speed runner like myself. But it doesn't work as a first Zone in a map-pack because the design choices would confuse a first time player.
The very first area of the game is wide open and devoid of direction; you even put a pillar in the middle of the stage that would block anyone from seeing the one, and only, exit the room has. After exploring the area thoroughly, all I had was a shield, and extra life, and two chaos emeralds to thank for it. Because of the circular layout, I actually wondered if I had accidentally entered a Match map in third person mode by accident. While I like the idea of having a balcony that can be scaled for secrets, the room is way too large and empty right now.
The next room is a fine little platforming area. I'd like to know if people who don't use a WASD /w Strafing control scheme would have problems with it due to the angles, though.
After jumping up all the way, the map tricked me into thinking it diverged into two paths, but really, the bottom path just leads to a spring that leads to the exact same destination as not falling does. Pretty pointless.
After that comes the room with platforms above water. I liked jumping across these platforms, probably because I'm just a sucker for narrow tightropes like that. Falling down into the water leads to an uninteresting water maze with a few fish; completely uneventful.
Only now, halfway through the level, do we get the first point of divergence. I like how the two paths cross in the room with the lava; very scenic and gives you a tantalizing view of the path not taken. The left path seems to be the easier path, with a couple of crushing walls and rivers that can drag you to the third route. Nothing to say about the crushing walls. They're just kind of there, and seem out of place because the mining supplies have not yet been added to the wad.
If you get swept into the water though, it can be frustrating to get back out. You have to run all the way back to hit a spring that can launch you up to a higher platform. Naturally, after hitting a spring, your instinct is to move forward (especially since the player will be disoriented as to what is north and south after taking the short waterslide). But no, after hitting the spring, you have to immediately turn around and head the opposite direction. The player should be filtered to the next segment, not lead to a dead end.
Going back and taking the right path, you did something a bit more interesting with the crushing walls here by placing collapsing floors in the area. I'd expect that many players will die at the second pair of walls the first time they play this, especially if they are like me and were running forward so fast that they only ever vaguely heard the sound of breaking dirt behind them. If the crumbling floor led to the water segment, or fourth alternate route, it'd be fine. But leading to death is just a cheap trick that will work once on a player and then be bypassed without challenge on every subsequent attempt.
The final room in which the goal is located is also unnecessarily large for what it accomplishes, and the way the sign is tucked away in a little alcove feels awkward.
Overall, this level is okay, but more things stand out as bad than good. You should think about what this level is meant to be, because right now, it isn't enough of a challenge for advanced players, and isn't simple enough for newcomers. I'm not going to offer any specific suggestions for changes, because I'm not a level designer, but hopefully the issues I've pointed out will lead you to your own ideas on how to improve on your design.
