Our submission for the ZFX Action XVI game jam. We decided to realize not one but three of the given restrictions. Therefore, the game

• uses only 4 colors
• has a resolution of 80x60 pixels
• can be played with just one button

The game is a horizontal shmup with nearly 20 waves of (steadily becoming more dangerous) enemies. Press an arbitrary button to thrust and shoot.

Have fun! 

Creative Commons Credits:

"Blipotron" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

"Cyborg Ninja" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

Used palette: https://lospec.com/palette-list/ice-cream-gb