Efficient Engine
This was merely a glorified fly swatting game, with substituted graphics. The graphic loops were nicely done and were simply but well drawn enough to keep the game interesting. The animation loops in the worms however lagged the game a little.
The sound was synchronised pretty much alright, but there were only a few different sound effects featured in the game.
The idea was unoriginal, I've seen many of this type of engine before, and I've seen many of this type of concept before, and you seem to have missed out on a personal twist with this one.
However, your engine was well built and shows you have some potential as a programmer. The different objects you could interact with were a nice twist and a pretty decent idea to feature in the game.
It was far too short though. With a bit of simple coding you could make the game get progressively harder and continue to an infinite number of levels. Limiting it to just four levels indicates you may have used multiple frames and conditionals to script the game, rather than dynamic coding which you should be aiming towards. My bad if you didn't.