This game was completely enjoyable right up until level 16. This level just absolutely killed the game for me because it was far too difficult. There just seemed to be no way to pass it. Even after the guards were dead, they'd still get up and start shooting, even if the turret was still up. The guards might as well have still been alive. There's just no point in playing at level 16.
I also didn't really like the feel of the controls. Maybe it's just not my cup of tea, but the control scheme was very poorly planned out. As for the feel of the controls themselves, they just didn't feel nice. I feel like I had some control over the character, but there was still a layer to it that I was missing, especially the jumps. Possibly consider increasing jump length and speed? That might do it, I'm not sure. The controls just felt kind of awkward for me.
The art just plain dissatisfying. The wall background remains constant all the time, and it just comes off as dull and simple after awhile. Everything just seems to be some kind of shade of gray, and the lack of color is noticeable and not nice.
I feel like the only place this game DIDN'T fall short was on the music and the concept. The music fit well into the game. It was just pleasant to hear. Could have used a music change every now and then just for some variation though, but it's still great. The concept could have worked quite well if you had pulled it off.
Overall, I just don't like this game much at all, especially that bit at 16. This game would have been acceptable for a first game that a beginner has made, but you could have done so much more, and the fact that such a good concept went to waste is very disappointing. Don't give up though, if this game received some slight revisions, it would be perfect. Perhaps we can see a Super Joe 2?