blame it on the ADD but I couldnt play the entirety of a side-scroller with somewhat unresponsive controls and not particularly gripping graphics. But this game obviously has potential and is programmed well for the most part, and seeing as how its v0.1 there will certainly be improvements.
Here are some ideas to consider though: When you attack in midair you can no longer move forward at the same time, but just fall straight down. The attack command also cannot be executed while the character is merely walking, but he has to stop and then shoot. While this is only a minor problem during the easier levels where enemies can easily be maneuvered around it seems like this problem on a harder level could be more troublesome.
But for the most part, good stuff. Keep it up!