I was asking ideas from my friends what to do at MS paint. Then friend said " Something where's lava". Well, I made this only because I was testing different styles, you can notice it from the rocks on the walls and from the lava. And about that darker place behind that guy, just testing. 
I would be glad to hear wich parts should have been made better. thanks. | 
Awesome. I think the hand coming out of the lava could have a cleaner shape though; its fingers look deformed.