First upgrade station is bugged. I was unable to pick up anything.
When it came to the poison gun, I was able to pick that up.
It is not clunky and the music is great. There is charm in it and I don't mind it playing in loop.
Overall an exciting game and a fun one, but the disability to pick up any upgrades isn't good.
I am playing in browser (Opera) and have not downloaded any extra materials. Also the game display is too big. Because of this, I shrunk the size of my browser display to 75%.