Here is the full list of all 10 Mutant Mudds Deluxe achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Collect all the spooky Water Sprites.
Collect 4000 Golden Diamonds, unnecessarily.
Unlock all characters.
Collect all of Grannie's medals.
Collect all 'known' Water Sprites and Golden Diamonds.
Beat the game. You'll know it when you see it.
Unlock the path to space.
Beat a REAL level without using the checkpoint (1-1 doesn't count!).
Beat a REAL level without getting hit (1-1 doesn't count!).
Beat a REAL level without dying once (1-1 doesn't count!).