Innoquous Engine 5 is a platforming engine that allows you to make a platformer with GameMaker's Box2D easily. You can also make games where the angle of gravity changes, and it's all nice and smooth!
The engine includes a controllable player object, walls (which perfectly work into GameMaker's room editor), gravity changers, and a demo room to try it all in. It's really easy to get into, and you can even take out the gravity changers and use the demo as a standard physics platformer.
Anything you make with Innoquous Engine 5 can be released commercially without any form of further payment!
This engine was made for Innoquous 5, which will not be using physics if it's made.