Many great ideas here. Directing shots by being the target is a really fun idea, and creates an interesting dynamic with how to kill the enemies indeed. The visuals, sounds, UI and UX were all very well polished for such a short jam - even for a team of 6. I played it several times. Feels like you're shooting for a top 100 spot, and I think it's deserved - I gave it a max rating.
Switching gears to be way more nitpicky:
- The control tutorial could've been better. The first time I played I didn't manage to pay attention to all the controls. Ideally, you shouldn't assume the player knows the controls before they've passed a very basic test where that control is needed. But it's a only minor complaint, since I got it after 2 or 3 tries.
- The title screen was slightly off, aesthetically. I get that it's retro/neon/Tron computer style graphics but it still gave me a way lower first impression than the actual game did. Even the settings looked smoother.
- The audio feedback for losing health is good, but it'd been nice with a slightly more apparent visual feedback as well. I know there's a screen-shake but late game there were many other screen-shakes, so perhaps some color along the edges or something
- The XP bar blended in a little too much with the hearts indicator to me - I didn't notice the hearts as well as I wish I did. Perhaps also because the game generally has lots of "thematic graphics" like the background grid of similar width, which has no functional utility and confused me ever so slightly. In a bullet hell / arena shooter with decreasing breathing room, it doesn't seem very useful to me to have so many uniformly colored elements display the information I need. Perhaps you could've altered the looks/color of the player for the 3 different heart "states" or something.
- For the first while I didn't realize that you could go on the top side of the tank too - perhaps you could've started zoomed out to the entire arena and then do a quick zoom animation into the normal camera.
- I didn't like the chromatic aberration effect on the enemies. It's a bit distracting for an action-packed game, in my opinion.
- My hitbox was not incredibly intuitive , especially for the player's odd shape - but fortunately it wasn't too big to feel very unfair.
- Minor bug: The music stopped after a while and didn't come back. WebGL version, Chrome, and having it in an unfocused tab for a few minutes.
- Very minor thing - in the settings, there were tick marks but you could also set the volume to half between the tick marks, which seemed a bit odd (but the granularity is much appreciated)
I'm also curious if there's more to the slightly odd name EB-87 than the meme, and what I presume is 1987. And also the Michelangelo head as a player?
Here's a few screenshots from my playthrough: https://imgur.com/a/dyS9Z0C