This game is really cool and has massive potential! Big fan of the gameplay loop, games where you can switch colors and actively uses it as a mechanic are always really cool. Just a few notes:
Pressing 1 and 2 at or around the same time causes a very loud feedback loop of the sfx used for switching colors. it actually stops the background music!
On controllers, the horizontal and vertical axis's are flipped, so holding up goes to the right, holding right goes up, and vice versa. also, there's no deadzones set for the left stick on controllers so even with no inputs, you'll still move in a direction as if an input is down. I had to use only keyboard + mouse to play.
During the section where you go north and the screen moves, the jumps you have to do always feel a bit too wide and it's tough to avoid taking damage from not making the jump.
I'll echo the sentiment that I'd prefer not having the timed sections, this is best for a special level or challenge mode instead of usual gameplay since bullet hells are already pretty hectic. Especially for such an early level too.
At the restaurant, since the game is getting pretty switched up it's probably best to keep it really straightforward, with no way to mess up. I forgot what ingredient i needed to make the hearty broth everyone wanted and just got kinda confused cuz I didn't get a chance to read what the instructions said. Could have the player make 1 dish with no time limit first, then start to serve other people after they get a hang of it. it also could just be me being a dork so keep that in mind!
Shift + R to reset the level seems to only work once in a while or for very specific levels of the build.
oh also to add to what Hythrain said, best to buff the ammo gain when you get low on ammo I felt like I was constantly running out of ammo after just a bit of shooting, i don't mind the collecting of ammo it just seemed too often. I'd personally not include the ammo overcollection penalty, I think it just slows things down a bit and doesn't quite fit cohesively with the gameplay.
To help optimize Unreal, there's a few things you can do, try using FXAA or even MXAA (if you're using forward rendering, which makes sense with the amazing artstyle) for anti-aliasing, switch from direct-x 11 to 9, and disable v-sync to keep lag down. if an object does not need to use tick for anything you can set them to have Start with Tick Enabled as false (even if they don't use the Tick node they can still eat up CPU!). Unreal is hard to optimize since it unfortunately is pretty heavy but there are things us Unreal devs can do!
This game is already very impressive, hyped to see how it comes along!