Because of a few mistakes, this game's unplayable.
1. This is clearly a bullet hell game, and the player's hitbox is too large. You should reduce the hit box at least the center of the ship. This is especially a problem during boss battles and enemy swarms.
2. No stage select. This is a problem because of the difficulty spike. Oh, and money gain to upgrade cost ratio is atrocious; I get an average of 300 bytes and the cost of upgrades can cost more than that. That means I have to play a level TWICE to get an upgrade.
The graphics may look nice, but they don't make up for the poorly executed game mechanics.