I thought this was a great game. The reason it worked so well was because it really had great detail. I know this has been done before with the "Centipede" games. What's cool about this is how it doesn't completely immobilize you and you have limited movement once you've collected all the blue stuff. The music is pretty nice and charming too. In case anyone's wondering, you are in fact only allowed to go to a drainage part once.
If you try to go back after collecting more slime, it's not going to work. The "Restart" button is helpful as ever, though. It looks like a lot of fine detail was put into all of the surroundings. It seems like a perfect environment for a bunch of blue slime to be. It's just a fun game overall.