Since I haven't played Tortured Planet in a pretty good amount of time, and it seems that the save states are now removed upon loading the mod, I'll have to leave my reviews of the zones based on pure memory because I'm too lazy and tired to play through the whole thing. So pardon me if I mix up some zones/bosses, leave out some alternate paths/hidden goodies, etc because this is going to be a really half-assed review.
Sunshine Atoll Zone-7/10
It's a solid zone with a good amount of secrets (not sure if you've added anything significant in the latest version). The Crawlas and textures did get a little repetitive, (as well as easy but since it's the first zone that's a given) but I liked the "fall through the forest canopy" idea with the boss.
Eruption Conduit Zone-7/10
Has many of the same positives and negatives as SAZ, although I didn't like the boss a whole lot. If I remember correctly, there were a couple upper paths in Act 1, which I liked. The factory was definitely a plus. Not much to say here until I get to play through it again.
Drowned Downtown Zone-6/10
Ehh. It lacks secrets, in places it's virtually impossible to get around the Skims, and the boss was tougher than Egg Rock 3 until I figured out to take out the Skims first. Then it just was an underwater version of the Techno Hill boss. The subway was a neat part, and I know that there were other sections I liked, but I can't remember them at the moment.
Snowcap Nimbus Zone-4/10
I was let down with this zone. Snow in the open areas slows you down and makes you sitting ducks for the Jetty-Syns, and the concealed Eggman monitors meant a lot of really cheap setbacks. The oil was out of place, and was an unnecessary hazard. The ice was okay, I figured in this zone it would appear at one time or another. After more a few deaths at the hands of the Jetty-Syns, bottomless pits (more often than not accounting to the Jettys) and Eggman monitors, my general strategy was just "F**k it, run for the exit and don't stop for anything". Which meant that if there was any secrets or neat places, I didn't see them. It does have very nice scenery, and I'm sure if I wasn't dying so much I may have found some interesting stuff, but I still didn't like it. 4/10 mainly for potential.
Gritty Columns Zone-7.5/10
Here we go. This was a very nice zone in my eyes. The visuals were enjoyable, although the wall textures in Act 2 do get boring after awhile. The quicksand was a nice effect, one large room with rising quicksand stands out in my memory. Crushers, narrow walkways, and bottomless pits all at once (I think) caused some deaths, but was enjoyable. Again, not really much else I remember at the moment.
Fume Shaft Zone-5/10
This zone actually didn't lag for me, so that wasn't a factor. However, I've never been a fan of fans over hazards (mainly because I suck at staying above the fan itself, and if you fly too low it ends up blowing you upwards and more often than not into the hazard). Other than that, it was pretty bland. Rocks, barrels, toxic slime, and fans. Also, the falling rocks really got old after awhile.
Liftoff Gantry Zone-6.5/10
I liked the first act, the second a little less. Act 1 had good gameplay, looks good, and reminds me of the 16-bit games (though in fairness SRB2 by itself does that). Act 2, again, I really don't remember much about it, but what I do remember was kinda bland. The boss was cool (assuming I'm thinking of the right one) with the switching gravity.
Spacewalk Zone-3.5/10
I don't want to repeat myself too much, but the only thing I remember about this zone is the theme and me raging a lot. The former was good. The latter, needless to say, wasn't. Cheap deaths run rampant through this zone, and I was on the verge of ragequitting when I finally beat Act 2. I have no idea how you're supposed to beat the boss, and after a handful of deaths at that point I finally ragequitted. A 3.5/10 for potential.
Alien Armageddon Zone-N/A
If I ever beat Spacewalk Zone, as well as the rest of the game, I'll prob'ly review this zone.
Oh, and please, please enable the save states again.