While I did put in 3 stars, don't take it personally because I LOVE this mod. Theres just a few problems that interrupts this awesome mod.
1. The ground pond is really great, my only complaints about this is that you cannot activate it when your in the air when you didn't jump. (Basicly, it should activate on springs, when falling, etc.) and couldn't after a dive.
2. Not sure if this is a bug, but in THZ if you get hit and knocked off to the gloop, normally what happens is you are invincible but still can't move unless like about 1 minute passes. For Mario though, when this happens he can't move but will slowly be left venerable.
3. The swimming... this one is what I dislike about this mod, its so weird, clumpy, slow, and uncomfortable. Moving mario is terrible in general, and you can't even stop swimming which is annoying because you can easily drown. Also the swim jump should be used multible times if you don't want mario to stop swimming in mid-air, you could just give it a medium cooldown instead to make it more fair.
Not sure if you were trying to hide it but how you said it lets us obviously know Metal Mario is his super form. It's a very great touch! What also makes it better is that he can't swim but can breath underwater, thats a win-win in my book! Though because he's made of metal, it doesn't make sense that he runs faster and jumps higher. Don't change the super though, its perfect as-is!
Other than the problems, this mod is outstanding! As long as 2 and 3 are fixed this would be the best 5-star rating I ever gave!