It plays very well! I really like the sound and camera shake that gets more extreme the longer you play. Looks good and sounds good as well, nice use of color and I like the design of the player character and the monsters.
As for things I think could be improved: maybe adding more monster spawners? At the start of the game I found camping in the corner to be a very valid strategy. Also, I would have liked to see how well I did after I died: maybe show how long I survived or how many enemies I killed?
Great job overall!