Feedback WIP Rivits FPS Sci-Fi Tank Game Called "Rivets"

I'm working on a simple game I'm calling "Rivets." Inspired a little from an old 80's game called "Battle Zone"
this 3D FPS will have 10 levels with each level being unlocked as you complete the mission in the previous level. So far I'm working on level 6 and still doing a fair amount of tweaks to previous levels, but levels 1 through 4 are basically done, I may do a few minor tweaks to them here and there.

This is my first real attempt at making a game, I had been so engaged in my Knight Rider Car software project I had little time for anything else so this is me taking a little break or diversion from that project for a while as I could pretty much go on forever with it, and forever is a really, REALLY long time lol

Anyways, for a first time attempt any feed back would be valued.... I like playing it but I can't trust myself lol