This sort of looks like it could turn into something great. The engine is fine but the layout is very sloppy. I love the animation when attacking but there's no running or walking animation sequence, instead, the character just moves to the right or left without moving this feet. This has potential for a future game but I think you already discussed the main bug in this.
The art is fine but when you are going to officially make the game, try making the layout looks less sloppy because right now the buttons are un-aligned like you did it in 3 minutes. Try not to use the default font too because it looks very un-professional. if you need an extra artist too, PM me... because I am bored. the game engine is decent but has some known bugs to it which you explained.
Overall, the test is pretty nice. Contact me when the game is finished.