Press Jump to Fall

Press Jump to Fall is an endless shooter where the only way to go down is to go up. Walk, jump, shoot your enemies and pick up heart containers! Try to go as far as you can go!

PJTF was made during the Game Maker's Toolkit Jam in under 12 hours.

Theme
My suggestion fits the theme of dual purpose design, because the jump button is linked to several actions. Of course you can jump, but you can fire while in the air, just like Downwell. Shooting downwards while in the air gives you a little jump boost. 

Enemies drop ammo when you kill them, so shooting is encouraged. The ammo-drops also kill enemies below you, so you don't have to spam the jump button when there are multiple enemies below you. It's extremely satisfying to see a whole pack of enemies disappear after shooting one of them

Another twist is that you have to shoot heart containers to retrieve a bit of health, so jumping is required for that as well.

In conclusion, you can have a lot of actions performed with just one button. In this case, the jump button.

Platforms
PJTF is currently only on Windows. Keep your eyes out for an HTML5 port, coming soon!

Assets and other resources
During the making of PJTF I used:

• GameMaker: Studio 1.4 for development (link);
• Paint.NET for graphics (link);
• FL Studio for music (link);
• BFXR for sound effects (link).

Within FL Studio I only used the NES VST plugin by Matt Montag (link).

Source code
For anyone with GM:S 1.x / 2, here you go:  (link)