Meh.
The guns felt useless. I could just ram all the enemies except bosses and then regen/get pickups while I found more. I did start dying around mission six but:
-enemies weapons and mine both felt really lackluster
-even with fast legs I was slow as balls
-why buy weapons when they suck? Every enemy in the game has a shield and a super-shield meaning you can either spend 10-15 seconds blasting them or you can spend 2 to ram 'em. It's a no brainer. On bosses you just have to kite *forever.*
IMO:
-Make speed disparities and armor disparities much higher so you feel like the choices you make matter
-Make enemy weapons and your weapons more powerful across the board, and again, more disparity. I should be almost one shotting most enemies with a powerful cannon and picking them apart with machine guns. There's more to that thought but meh.
-Make ramming not instant kill (same goes for bosses) and not even a tactic. It's retarded. As soon as I realized I could do it it just became a boring game with a few "whoops, I died to a laser" moments; or "whoops, I ran into a boss/too many enemies."
-Losing all your money and XP is a bit harsh too; especially because the upgrades are so useless anyway.