A sort of boss rush game I made in the middle of high school with an ol' version of Game Maker (GM7, IIRC). Music is absent, and the sound effects are rather crude, but this was one of my first efforts of making a shmup back in the day.
Controls are as follows:
←↓→ to move around
Z to fire your ship
X to slow down your ship
C to release a bomb
The scoring system may take some explaining, seeing that it's a bit complex how scoring works in this game.
Each turret is worth the amount of base points below your current score. You raise this by collecting coins that are released by the turrets when their health is critical (as indicated by a flashing red turret). After a while in critical condition, the turret will self-destruct, granting you the amount of points indicated below your current score.
Coins are attracted to you when you're not shooting and fall freely when you are.
You can shoot at a turret again while it's at its critical state to reset its self-destruct timer. This is helpful in milking turrets; however, keep in mind that each stage is timed, so it's best to be reasonable when milking the turrets. Also, the longer you stall time, the more powerful the turrets' attacks become, so proceed with caution (and get bonus multipliers as well for it, too).
Raising the base value of coins requires that you collect all of the coins on the screen before letting another coin appear. The next coin that appears when all the coins are collected will have a base value raised by 10, up to 150 per coin. You can easily do this by getting dangerously close to one critical turret and raising the value like that.
You also have bombs at your disposal as well. You gain 2 bombs per level you reach and 2 bombs per death. Bombing clears all bullets AND 150pt. coins on the screen, in which said bullets and coins are converted into light blue bonus medals that are automatically attracted to your ship. Said medals grant you your base shot value, which means that every bullet that hits an enemy will grant you that many points. If you get more of these after you max out at 10,000, the value goes towards the turret's base points. Using bombs is essential for getting a really high score.