Squares are topics/points. Pluses are additional points. Minuses are just comments.
■ Interesting movement. I've never seen a mouse-relative movement system like this before. I like the concept of that, but it's not done well.
You can capitalize on that by trying to design the game around it or change it to make it more approachable to new players.
If you choose the former, a feature to consider could be locking on, so the player is less confused while moving around - the mouse snaps to the closest target or the next. Could be dumb, though - lock-on features are hard to make good.
+ It would be interesting to add a feature to instantly turn the player around.
+ You could also try getting rid of moving forward and backward altogether, be that literally (by making the player not able to do so with W and S) or by design (having the levels, enemies, and gameplay in general, make that the most fun or most effective way of playing).
+ Maybe the aiming could be slower to make movement less jarring? That and the cannon rotates separately from the body. That might change the game too much though, so I don't mind this not being implemented, but you should look into making the movement less jarring.
+ Another idea for making it less jarring. Have the movement be relative only to the direction you're looking, not to how centered on the screen the cursor is.
I don't think there's a need for the movement to take into consideration how close the aim is to the center of the screen.
I still think you should be able to rotate around where you're looking at, so don't set that pivot point to be too far away from the player, but also not too close.
+ Alternatively, you can Not do that, but make aiming inward or outward slower.
+ You can also try making the game pace slower. The fast pace of the movement and bullets is better fitted for level design with open/larger areas.
+ It might be worth looking into whether the aiming reticle should stay still in relation to the player UI or to the environment, and seeing whether either is any less jarring.
+ I think it would be good for the player to see their turning diameter. Meaning, a circle that intersects with the aiming reticle, whose diameter is of the distance between the reticle and the player.
+ If you end up giving up on this style of movement, you can just make it like BubbleTanks 3, AwesomeTanks, Hotline Miami, or any other top-down shooter. I think that would get rid of some uniqueness of this, but if you just can't make it work, it's understandable. It's a lot of development time to make this work well, you might just wanna be familiar with typical top-down shooter game design before trying to break the mold.
- I just noticed you can change the control style. While I'm glad to have the option, you should design your game around one of those, not both. I personally was having what I can only describe as frustrating fun playing with the first Control Type (A). Note that I'm biased in regards to this because I like Rally racing games - you wrestle with the controls in that as well, though there are tactics to it in those games.
+ It seems that I move faster diagonally than forwards and sideways. I'm not sure.
- From here on I played with the Control Type (B).
■ You should make item pickups more visible. In the off-chance they're coloured according to my vehicle's colour, remove that feature.
■ I'm not a fan of most obstacles being timed obstacles that are closed most of the time. It would be good to have breakable ones (see Awesome Tanks) to break up the pace (the animation and sounds go a long way to making the breaking feel satisfying).
■ It would be good if the game pointed me to the next nearest crystal (whether it's physically near or near in terms of pathfinding is up to you).
+ Alternatively, you can implement a minimap showing you where the close ones are, and that shows you where you have gone (with a traced path), without spoiling the level.
+ Remove the red and white 1/8's of a circle that instantly spawn in rotation around crystals on crystals you've already collected (in case you died and have to get them again)
■ The enemy that is stuck to walls and shoots you bricks the performance of the game. Fix that.
+ They also shoot WAY too fast. They're not a fair enemy. Give them a cooldown, at the very least.
+ They also take way too long to kill.
+ They also seem to crash the audio engine at times. I'm not sure if that's what's happening - it stops and comes back after a couple of seconds.
+ The enemies with what look like shields around them seem to take just as long if not less time to kill than the enemies without. That doesn't make sense to me. If they're supposed to be faster, make them a triangle instead. Purposeful visual design.
+ Make the fact that enemies are taking damage more visible.
+ Add ranged enemies that can follow you. Either make them move more slowly or shoot at a slower rate than turrets.
++ Okay, I found the fly looking thing that follows and shoots you. They're way too fast for the close-quarter levels we have here. They turn way too quickly as well.
+ The single wall that rotates towards you turns way too fast.
+ It's easy to get stun-locked if you find yourself in a bad position. This encourages you to play cowardly, by running away, picking enemies one by one, or cheesing them. Not to mention the quick walls and extremely fast projectiles.
■ I noticed you can shoot projectiles out of the air. The game is basically asking for you to implement missiles. If you add them, don't make them turn too quickly, and have a certain lifetime.
■ The standing turret fires too many rounds quickly. Make the enemy more telegraphed - meaning, you should be able to better tell what it's gonna do next, in a way that doesn't trivialize the attacks of the enemies by making them too easy to dodge (meaning, in a balanced manner). You can do that with charge-up sounds and limiting the turret rotation speed.
■ It doesn't seem like a good idea to put 1/8's of a circle that instantly spawn in rotation around crystals unless you can avoid the collision glitches when they inadvertently spawns on top of the player. Alternatively, you can use the rotating circles with an opening (rotating obstacles) instead.
■ The aim is off the further away from the player the aiming reticle is. https://streamable.com/m6hnu That seems like a bug to me.
■ The shuriken weapon also lags the game, albeit less than the wall enemy.
■ The level design should not be maze-like: that kind of design is not fun - it doesn't respect the time of the player. Coupled with the timed obstacles, even more so. Now, that actually might Not be the case, it might just be that it's unclear where to go next. If so, see the above.
++ No, it's not just unclear. It is designed like a maze. Some corridors lead to empty rooms. They must have something.
+ I think the walls would look better if they connected to each other instead of having holes.
+ I think the floor textures should vary in different sections of the level. At least in pattern.
+ I think the background would look better if it had a vignette effect on it instead of being a solid color. That would be great, but experiment with what looks good - maybe a slow animated smoke-ish looking texture, or a slow animated noise texture, could look good. Might ruin the clean look of the game though, it really depends, also can't be too distracting. Experiment. But the vignette would go a long way.
++ I just noticed the background is actually just the part of the wall that's darkest. That can look better. Add a gradient that gets darker the further away from the wall it is.
+ Vary the hues of grey in the game.
+ Have the player get a checkpoint upon collecting half of the crystals. This might not be necessary.
++ Yes, it's definitely necessary.
+ Have the gfx of particles that you and enemies shoot decelerate as they get away from the center of the impact.
+ You could make the foreground stand out from the background (the floor and the void behind the stage) by adding shadows around the walls, around enemies that are off the ground, and turrets(specifically, the part that moves). See "Darkwood".
+ Get rid of the stubs sticking out of the corners of the walls. Took me a while to notice, but it doesn't look good.
+ Have a stage select screen and make the game have less stages, or make them better paced.
++ The game is horrifyingly long. I'm legitimately considering not finishing it. I had to make a map myself to finish one of the levels.
+ The spinning obstacles could be substituted by a door that you must wait for a little second before it opens. Or breakable blocks.
+ The player's cannon should not collide with objects. The hitbox should be consistent.
+ I have seen this thing many times http://prntscr.com/p4h8ui and I have no idea what it is. If it's an item you're supposed to be able to pick up, I can't do that.
+ I assume I'm on the last level. NEVER make rooms filled with enemies without any thought put into like this, it's Extremely lazy and Not fun. This sucks big time. It also sucks that it lags so much. That kind of design tells me a game is not worth anyone's time.
- I hope this is your first or second game because this is really a chore to play. I've been playing for 3-4 hours, this is not okay for a browser game.
+ Have toggleable autofire next time; instead of hold to shoot.
- I finished it. http://prntscr.com/p4hfia (at 20:18; I started at 16:11) That was not fun. Please, have people playtest your levels.
+ If the game is supposed to be insect-themed, have more insect-themed enemies instead of random shapes. I thought this was a surreal world apart from the player and two enemies looking like insects. Give them legs, antennae, wings. They're supposed to be robots, that's fine, make them and the levels look more appealing instead of this dull grey. You can start doing this just by varying the hues of grey. I think the game would be more visually interesting if the environments were a mix of robotic and natural aspects and objects, though mostly natural. Use big/medium objects to show to the player the scale of the world, as well, like Pikmin.
+ One thing I noticed at the very last room (with enemies) in the game - the 1/8's of a circle that instantly spawn in rotation around crystals, well, they're not centered. It's almost as if a different object altogether is being loaded in (I hope that's not the case) a very very slightly different location. It's off-center.
- At the end of the critique I was gonna give it a 2.5 and tell you to imagine it was the rating that has a guy with a smirk on his face. I'm not doing that anymore. I was content writing this during the first 90 minutes but now I'm just exhausted.
Somehow, I still have a bit of energy to be patient enough to write this: Ultimately, you should be proud that you finished the project. It's a game. Games are hard to make, and any project is hard to finish. Don't get attached. It's a stepping stone for the better, future you.