Riddled with holes
There's an enemy on level 8 who couldn't be killed, making the rest of the game unplayable. The game needs a thorough combing for any fatal glitches like that one.
Other than that the game's biggest handicap is its control scheme. The button controls are cramped and it's too difficult to move and defend at the same time. Perhaps instead of having click be attack, make click defend instead. Then you could use wasd to move and space to attack and leave the jumping out of it. Just a suggestion, but whatever you decide the controls need a change.