Thank you for your thorough review.
The stock 3rd person controller from unity actually gave me free-aim, and i played with it for a week. Often times i got frustrated because i "just wanted to shoot at this enemy". After adding the lock-on system, i (and my playtesters) can focus on dodging bullets while shooting at them. It enables them to play more intentionally. The moving tank also magically missed the enemies sometimes so i happily left the bug in and require the player to stop for a tiny moment in order to surely hit the enemies.
For the buildings, i did come across some building assets, but i could not find ones that are blocky enough to enable the tank's little platforming actions.
Normal enemies are a bit tricky. I am afraid if they can move they will dodge too many bullets, so i hesitated to give them movements. But i do agree that looks too static for anyone's taste. (Or i just make the bullets have bigger invisible hitboxes...)
Thank you again for trying it out. Have a nice day and good luck on your journey.
P.S. good one spotting out the volume inconsistencies. It bugged me a bit even playing it myself. Will need to change it post-jam. (Future me: take notes!)