Overall a nice game. It's a classic concept, that is well executed with an interesting twist of quickly changing between the different arenas.
I will divide my feedback into several sections. Don't take it too harshly, it's just a bunch of stuff I noted during my time with the game that I think could be improved or made better, I really had fun with your game, otherwise I would not be writing this extensive feedback:
Gameplay:
- Nice camera movements, good job on that.
- The feel of the game was nice, although the powerups sometimes felt a bit unrewarding (does the shield really shield me?).
- I also did not notice there are even some power ups for my first couple of playthroughs.
- The power-ups were a bit elusive to pick. I would increase its hitbox a little bit, it felt really bad to miss it by a tiny hair and then be thrown to a different dice face.
- Nice touch with the shifting spawning points, it made the gameplay more interesting and chaotic.
- The game usually ended for me with a small fast enemy spawning next to me and killing me before I could react. It would be nice to have the enemies for example slowly build-up speed after spawning or have some FX warning the player that they will spawn soon.
- I like the high score and overall menu layout with all those "start game", "try again" etc. options.
Graphics:
- The color palette seems a bit basic and without much meaning apart from blue good - red bad. I think it could use a bit more tweaking to create a more cohesive experience. Perhaps look up some color palette generator and take inspiration from that? On the other hand, I appreciate that the colors were not obnoxious and annoying, which is especially hard to achieve when only using basic 3D shapes with no textures.
- You are using the default Unity skybox and unfortunately, the skybox is very visible in your game. There are many awesome free skyboxes on the asset store that you can use. This would improve the "graphics" a lot for very minimal effort. Or if you really don't want to use any external assets, put the whole thing into some kind of a box yourself.
- I guess you are using URP? The default settings in URP do not use any antialiasing and it is very visible in your game. Turn AA on and it will instantly look much better. Turn on bloom for extra juice points.
- I like the particle FX for shooting and especially destroying enemies. Good job on that!
- The enemies all look very much alike, the only differentiator is the size, but it's hard to distinguish that with peripheral vision and thus it is very hard to differentiate enemies that are further away from the player, especially when there's a swarm of them. It would be nice to have some kind of obvious visual differentiator.
- It is totally OK to use basic shapes (it gives the game interesting abstract feel of "kill the red bad"), but even with basic shapes you can do a lot of cool flashy animation stuff. You can squish them and stretch them, make them bounce and so on. If the shape of the enemy did some kind of visual feedback on the hit for example (apart from the color change), it would add quite some juice to the game.
Sounds:
- I like that you created your own music for the game, but frankly, it feels a bit disturbing after a while. It feels like both the synth and drums are trying to play main melody as well as set the rythm. It would in my opinion work much better if the drums set the rythm (and played repetitive rythm section all over). This would allow the main synth instrument to vary the pacing a bit and play an interesting melody theme.
- I like the SFX throughout the game, but...
- The shooting sound could be a bit more 8-bit to fit the game and less realgunlike.
- The machinegun powerup changes the gun sound but then it somewhat stops working properly.
- The previous shooting SFX is audible when jumping but not otherwise.
- There is little SFX feedback from the enemies apart from dying. You could add for example:
- Hit SFX
- Proximity to certain dangerous enemies (like the fast ones)
- Spawning of enemies (especially the boss-like large ones)
Miscelaneous:
- Windows build v2 does not work, I got stuck on falling intro.
- Sometimes the game was a bit choppy. I blame WebGL, but this kind of game genre begs for some optimization in form of pooling the enemies for example.
- Entering the settings for the first time mutes all sounds.
Once again, a good job on making what looks like a fairly finished game, keep it up!