In order to rotate the pieces, you have to tap on them while they're on a rotate spot in order to open up the rotate menu. This may have been better represented with some kind of button pressing visualization, since as it is, it looks more like you're supposed to try manually rotating the piece with your cursor.
Competitive multiplayer can afford to have a hardcore playerbase because the players determine how difficult the game is. Coop single/multi is much more reliant on a playerbase that continuously renews itself, and you need to make it inviting. All or nothing means much less players get in through the gate, and then when that loot isn't worth much in the store and you need all these different things for a random chance of equipment you want, the game is presented in a poor light to the players that do get through, especially when the bullet system is not explained until you hit that point, and that bullets are not analogous to keys and begs the question of why the store is only selling lockboxes in the first place. Is it more fair to players in the long run to let them choose what their grind is going towards? Yes. Does it discourage new players from getting past the initial gameplay period? Also yes. It's tough to find a balance, but I have faith in you folks.
No, see, people like picking up lootboxes, not buying them. Putting the key system on top of the lootbox buying system basically means there's four steps to the loot system before a payoff (loot, survive, be able to afford a chest, be able to open that chest) where two steps (loot, survive) should have been the basic ones. If we're counting bronze chests, they should be either significantly less expensive to compensate for the fact that they have trash items in them (because the only players that would buy them don't have any equipment and have a hard time surviving to the first checkpoint, much less being able to loot with a large army of robots riding their butts and having to use some of that gold to restock supplies) or make the first few checkpoints shorter to get to, or stop the enemy spawns on the first few rounds of looting so that players can get into the groove of things so that they don't ragequit after giving the game a shot and dying with zero reward.
Heavy grind. Low rewards. Coin pickups. Bullet pattern almost always guarantees damage since hitboxes are 2d instead of isometric. Missing sound. Promises full game on other site and forgets to put sound in this version. Not sure if stolen or just badly uploaded. Forget it.