I bought the 1000-cost starship for now and maxed out its fire rate, but honestly, the game feels pretty broken in many ways.While the mouse tracking is fine, the ship stops moving entirely if the mouse pointer leaves the screen. On top of that, you can't even reach enemies or items at the edges of the screen without using the keyboard as well.The fire rate upgrade item seems good at first glance, but it actually scales up the enemy rank, causing an endless wave of enemies to spawn constantly.To make matters worse, the firing position of my own ship is completely uneven, so the bullets don't even go where I’m aiming, which is just frustrating.Requiring 1000 diamonds just to get the starting equipment for a retro shooter is ridiculous.To be completely honest, I don't like this game either.