Hail to the new Sonic...
This is a good game. As far as games on Newgrounds are concerned, this complements the Portal's good games and is in the similer vein of Sonic and Mario as far as platformers go, but there are flaws with the game which stop it becoming a great game.
The graphics are solid enough, but sadly I was tired of the emerald island/floating island thing. I think that better levels with new backgrounds can spice up the gameplay. New enemies would also be good. There is a certain amount of style evident within the flash, and it shows. This is a cool blob, but he reminds me much of the Weebl and Bob, except in Blob form.
The sound or prehaps the music could have been a little better. Prehaps you should go for some good background music like...Sonic 2. I think that sort of style of music is kick ass and would complement the blob. The game itself is solid enough, but for some reason I keep falling through cracks. I like the double jump (intentional?) as they kept getting me out of trouble.
Overall the game could have been great, but you need to improve on the flaws. I await your next game...BRING ON THE BLOB