I played your game and is working well, here is my feedback...
- cool start screen! for some reason set to winder then my monitor so i had to zoom out
- there are weird sound effects happening when i click away from the window
- i thought maybe it froze up when i clicked deploy, maybe add a loding message,
- the framerate is very bad it is hard to play.
- if you are using canvas2d that can be slow to render, maybe try a game engine like LittleJS
- in game graphics are good but could use refinement. like the player sprite could have different angles to aim the gun.