A few suggestions:

Grenades: This is a snap to grid programming, makes it very difficult for precise placement. This may be intended, but is annoying.

Water in river(Fire slug cave) : If I want to attack these slugs, the water in the river/creek doesn't get you wet. It probably should.

Contamination: The entire screen(4K) and off the screen is bamboozled with contamination. Crazy radius, are you sure this is as intended?