I like the concept, but first I didn't know how to shoot or walk and then I looked into the instructions on the itch page, maybe next time you should do a small tutorial.
I also would do that the enemies can you from different areas, because almost 90% of them (or all), came from a specific bridge, so this made the game easy.
Sound effects are important too, at least for the shooting
And add a Health-bar, so when enemy collides you it reduces your health, and pleaseee use time.timeScale = 0 when the game ends, because the enemy keeps pushing me and it causes me a headache.
Good job and good luck. :)