I just tested something and figured it out
-In fullscreen, the tomatoes were twice my speed
-in the normal view, they were equal
-when I shrunk the page to 70%, they were 70% of my speed and I had an easy time outpacing them
It's the window size messing with things. Worse, the window doesn't scale which means if I shrink the screen to slow down the enemies to a reasonable level I can't pick up the gun to start.
I'll bump the game design score up two because the unfair speed was unintentional.