Very nice sprites and a fun little tune! I would like if the game was a little more forgiving, as the controls are a bit difficult to get a good feeling for and only having a few seconds to learn them even in early levels seems a bit hard. Also, I had a bit of trouble figuring out what I was even supposed to do in the first place; adding a tutorial or choosing a different coding (replacing the barrel with a key, for example) could help with that, I think.
Other than that, a very promising start. Would love to see this being continued and polished a bit more.