Build and Shoot

This is a cool side scrolling looting game that is free but unfortunately, kind of dead. But it is open source!

Here ya go:
http://www.epicinventor.com/

Go ahead and make your own game out of it. It needs that. :)

I know that game and played it for some time, but it got boring pretty quickly. It's basically exploring and looting, and it has the very big disadvantage that you can't modify the terrain.

But, the source code is released so you can edit all you want

In that case it would act like a game engine or a base for a new game. If somebody wants to make a similar game, he will rather write everything from scratch instead of taking something like that.