This was real fun. I liked the style a lot. Music was cool as well.
Feedback:
I couldn't access shop when it disappeared from screen.
I'd get stuck on blocks a lot when trying to jump over or on them.
The music would go away when I'd leave tab, until I like collected something. Sounds would stay though.
It would have been nice if there was a dash or run mechanic for faster travel.
The shop mechanic was great. Everything about it from the slot machine to upgrades.
Loved how I could explore around after the wave to collect coins.
Nice job on adding a sensitivity setting.
I liked the variety of weapons.
The hands never worked for meelee.
Nice stats mechanic.
The bullet hit shot particles would linger on the enemy bodies.
Nice increase in difficulty over waves.
Good variety of enemies.
Overall, nice job!