The basic gameplay is solid, but I feel you should lean into the Smash TV approach of more enemies, but have the enemies be less threatening individually. You also might want to take a clue from the Genesis version of Demolition Man's top down levels and have civilians to save/not shoot, and objectives to complete other than 'get to the end'.
I'm not huge on the genre, but you seem to be wearing your influances on your sleve. Keep it up.