Nicely done. The concept is good and you executed it well.
It started out easy and then got a bit disorienting with the multitasking.
I loved the music and the retro feel.
I only feel the monster's dying voice could have been a comic, high pitch yelp instead of a low burp.
All that aside, it's a good game. I expect more retro games from you soon.
Cheers!