Gotta give it a review, though it's my first ever review
First of all: You didn't include the folder with the custom graphics in the download and now it just has the original graphics, which is a bummer. It was a really short level with a hard section in the beginning, which was odd. It also was a bit of an enemy spam. Some sections were really empty and in the water section there weren't any enemies. Also the bubbles felt kinda unnecessary.
Some nitpicks:
At the top of the water aren't any waves so now it looks like a blue square.
Also the water doesn't go through the pipe (I now this sounds nit-pickey but for me it looks kinda weird
)
At the end is a pipe that doesn't exactly line up with the other pipe. Also the blocks at the end felt out of place.
Music: 3/5 (Couldn't really rate because mayby there was custom music, so yeah)
Enemy placement: 2/5 (Could have been placed better, though the place their in doesn't feel out of place)
Level design: 1,5/5 (Sorry about that, but the beginning looked better than the rest)
Overall I give it a 2.5/10. In the beginning you have a lot of munchers and piranha plants which is your theme of the level, though later in the level there weren't any munchers and piranha plants at all! Don't worry though, keep making levels and eventually you will get better 
