Well, I'd like to bump this thread to get more comments in it, and I might as well vote on them myself now that enough time has passed.
Greenflower Zone Act 1 - 5/10
Really solid intro level, and nothing more. I still love the useless area with the house and Sonic's emblem. One of my favorite experiences early on playing SRB2 was figuring out I could get up there as Sonic.
Greenflower Zone Act 2 - 10/10
I'm probably going to get a few looks for this, but this was and still is one of the few near-perfect SRB2 stages. This level has so much to do and see, with a simple main path and TONS of secrets everywhere. It took me months to find everything there is to see in this level, despite how relatively small it is compared to the other stages in the game.
Greenflower Zone Act 3 - 5/10
Basic first boss. Serves its purpose and nothing more.
Techno Hill Zone Act 1 - 4/10
This level has always been solid but it never really clicked for me. It feels so linear and personally I find it slightly more boring than GFZ1 because there's less to do. That being said it's not a BAD act. Just not nearly up to the quality of the rest of the game.
Techno Hill Zone Act 2 - 6/10
Starting the levels with actual challenge is this little level. I don't like how little there is to do in this level, as the alternate paths are so much slower than the main path so they're never used. Some of the secrets in this level are quite clever, though. I still really like the tunnel with the slime that leads to the second emerald token.
Techno Hill Zone Act 3 - 9/10
While the level is kinda cheap, this boss is excellent. Simple concept with a few basic rules that's just really interesting and interactive once it starts moving.
Deep Sea Zone Act 1 - 7/10
My main complaint in this stage is how the framerate just dies sometimes. I really like the Knuckles path and emblem, and some rooms just move a bit slow, especially the second room on the lower path, with the moving platforms. I do really like the usage of floating blocks to crush the player and end up as platforms used throughout the level.
Deep Sea Zone Act 2 - 8/10
The first of the really truly large stages in 2.0, this level is just huge. I love the block room and the water slides. I'm a huge fan of the constantly changing platform mechanics and the fear of being crushed without actually resorting to "crushers". I also like seeing some of the old DSZ work I did actually end up in the final product, but that's just me. =P
Deep Sea Zone Act 3 - 7/10
I really like the mechanics here, but the boss just takes too long.
Castle Eggman Zone Act 1 - 4/10
I like some of the content we've got here, but it just feels so empty through most of the stage, with long areas, huge jumps over areas with no detail, and sections that don't have alternate paths at all.
Castle Eggman Zone Act 2 - 3/10
Ugh. Some really awesome ideas here let down by ugly rooms with horrid framerate and bad production values. Hopefully we can fix this level so the awesome ideas get a chance to actually shine through.
Arid Canyon Zone Act 1 - 9/10
Another stage that goes by the GFZ2 school of exploration, there is SO much to do and see in this stage. The level is absolutely massive and there are tons of little hidden things to find. The main problems I have with it are a few uninteresting sections, especially the end. Fortunately the rest of the stage is so awesome that this is ignorable for the most part.
Red Volcano Zone Act 1 - 6/10
This level really feels dated. With the exception of the new lava wave bit at the end, the zone is just simplistic and boils down to jumping on collapsing platforms over lava. We really need to add some new gimmicks into here.
Eggrock Zone Act 1 - 8/10
I still remember my jaw dropping on the first beta of this I was sent. The texturing sucked and it was glitchy, but then as now this level just blew my mind. Completely new gimmick after completely new gimmick in a hardcore level that's more like Scrap Brain than a 3D Sonic has ever done before. The main problems are a few completely uninteresting gimmicks and the final room being totally cheap. It could also use some expansion considering how much larger ERZ2 is by comparison.
Eggrock Zone Act 2 - 10/10
While I have a few nitpicks in places, this level is just so massive and completely awesome that those nitpicks are just irrelevant in the big picture. This is what the final level of a Sonic game SHOULD be. Huge, epic, and challenging.
Eggrock Zone Act 3 - 8/10
This boss is pretty sweet, although it'll be better once there is something to tell the player how to beat it in a previous stage. I still really like the mechanics of having the missile fly back at the boss, as the controls in that feel so natural it's kinda unbelievable.
Jade Valley Zone - 9/10
I've really grown on this map a lot. Just big enough to hold lots of players and enough rooms to block line of sight, but still be small enough to always be able to find your opponent and make sure the items are all in relatively easy reach. I also really like how the vertical variation makes the level play differently as Sonic, Tails, and Knuckles.
Noxious Factory Zone - 6/10
Well, this map is insanely intense, but it's lacking in a few areas. For one, the outside area needs some dramatic work to make it look less ugly, and it always degenerates into a spamfest inside. The SRM is really hard to reach in any kind of lag, and it's generally better to just spam weapons instead of trying to get an advantage with the items.
Tidal Palace Zone - 8/10
I really like this level. The changing water level makes the stage have a weird dynamic to it that no other stage has, essentially creating two stages that alternate every 45 seconds. The changing tides make for completely different strategy than a normal stage, and there is nothing more satisfying than knocking someone off an air bubble to grab it yourself, and then watch them drown helplessly.
Thunder Citadel Zone - 8/10
I'm quite happy with the revamp on the outside, except for that damn tower. I still can't figure out what to do with that. Otherwise, this is a great level with lots of depth. To everyone who plays with me and doesn't seem to realize that you can get like 60 rings in the stream, it's your loss. I really like the small alcoves everywhere despite how simple the level design really is.
Desolate Twilight Zone - 8/10
Another solid map that plays differently from the rest of the rotation, this map is just so wide-open that it leads to very different combat than the other maps. Rail is epic here and the lack of rings makes Auto a dangerous proposition. The battles for the SRM are frequently awesome in the only confined area of the stage.
Infernal Cavern Zone - 7/10
I know I seem to be in the minority here, but I really like this map. Here's a hint for those that seem to hate it: Stop thokking to get away from people and start doing it more methodically. Thokking without thinking here will lead to you getting hit. So much of this level is dangerous and cramped while never actually restricting the player's view of their surroundings. I do want to get those stupid flame jets fixed so you can actually see where they come from, though. It's quite annoying even to me.
Sapphire Falls Zone - 7/10
I'm really happy this turned out as well as it did. I was quite concerned that this level was too symmetrical even after breaking it, but it looks like we got it right. Personally I find this level a bit too small but it works great in smaller games.
Meadow Match Zone - 6/10
Har. I originally ported this as mostly a joke and we ended up having enough fun on it to put it in. This isn't really a great map but it's fun anyways, especially in smaller games. Railing people off the springs is still some of the best fun to be had in SRB2 multiplayer.
Lime Forest Zone - 6/10
This map really shows its age, with its cramped bases and linear design. The new visuals help a lot, and the team rings make it tolerable, but the level is still really small. It works great in smaller games, though.
Cloud Palace Zone - 7/10
I still really love the bases on this map. Something about trying to camp the springs up to the flag being hard but possible is enjoyable to me. I also really like the midfield to this map being completely straight in the center while still having plenty of alternate routes to get to the other side.
Silver Cascade Zone - 8/10
Team rings are the best thing ever to happen to this map. Defense is a viable option here and I love this fact to death. Quicker ways to get to the other side also really help, as in 1.09.4 it took too long since you always had to take the water path.
Icicle Falls Zone - 6/10
Brutally quick and lethal, this level is great fun, if completely impossible to defend in. Hopefully the bases can be redesigned a bit to allow the defending team to have SOME chance.
Twisted Terminal Zone - 6/10
I love the design of this level, but the execution leaves a bit to be desired. The main thing is that the bases are impossible to defend and a tad too large. The central passage is completely awesome, though, especially thanks to the reverse gravity.
Nimbus Ruins Zone - 7/10
I know people hate this stage, you don't have to keep telling me. The thing is, I also know a lot of people really like it, and I'm in that camp. While it's pretty much impossible to live for more than a minute in this level, the design makes it more about running the flag than anything else, and a successful run back to your own base is almost assured to be a capture. There is also a sick part of me that just loves to rail people into oblivion.
