I think I completed the game, though' I cheated, I did not talk to the boss so he could not fight back. I run into a situation where my commands did not respond anymore after that (I think it happened another time before) so I am not sure if there is in fact more, if we're meant to kill the mosquito, especially.
I like the choice between two characters, including the second one effectively acting as an extra life. I died a couple of times before using strafing efficiently. One character chatting with the ghosts of dead enemies in cool, and the warped door line is hilarious.
The game was almost unplayable on Firefox and worked fine on Chrome for me, in case it can help someone else.
Overall the game is fun and I enjoyed it.