Using Game Maker Studio I have been working collaboratively with a friend to create a space shooter.
See the GIF here
1.) You can quick select your weapon by touching the center of the screen cross hair.
2.) 3 Types of weapons exist. Laser which goes straight up. Rocket which hones in on the closest enemy. And Lasor which hits everything
3.) At the end of a wave you can buy upgrades
4.) hitting an enemy with a matching laser color builds combo points for a score multiplier
This game is in Alpha.