It's very difficult to aim right, making the game very hard to play. Maybe player and enemies should move on a grid instead of moving freely. Another solution to try is to make the player move by holding a direction, but just make it aim in a direction without moving if a direction input is pressed and released instantly.

Also, please set a window size of x3 or x4 by default next time!

That was a very fun game! The weapon upgrades were great and the game was quite thrilling!

Very fun little game, love the purchasing new weapons, each weapon feels unique and a big step up every time you spend the money.