When I started the viewport was only showing me the top half of the play area. It looks like your viewport settings are using the defaults for landscape, but your game is designed for portrait. You should be able to edit the "Viewport dimensions" in the itch.io settings. If you just flip the width and height it should be fine. When I used fullscreen it showed the rest of the game, but the game did not scale.
The game could use with better instructions. You mention E to fire, but should also mention using the mouse to control the position. With the only control listed being for the keyboard I expected all keyboard controls. You comment the colors being good or bad "sometimes", but do not explain how that works. You also don't say if you should hit the colored spots, or go between them. They generally spawn in pairs, making it look like goal posts you should go between, but playing it seemed like you should hit them. In general, a bit more explanaition, even if it is on the game listing on itch.io, rather than in game, would help.
It also felt like sometimes the red and green spawned on the same spot, but you could only see one, and it may have been random which one triggered. I'm guessing that may have been what you meant by "sometimes". When I pressed E and did not hit a colored spot, the tape image did not always respawn in the viewable area, though pressing E it did shoot across the screen.
The sound when going negative was really unpleasant. The visuals were not that great either, but the sound had me turn off my speakers.
You've got a start for a simple game here, but it will need work to be enjoyable. Helping the player know what to do and how to play, will go a long way to improving things.