Developing the idea for game

I'm thinking is to make a cube sprite and its goal is to go into a vortex... it has to go past many obsticles and the cube man can jump over them.

To make the game go harder it has different levels which it has to go past. If the cube land onto a red bit of the surface it dies and the person has to start again from the begining of that level and try to pass the river and and go into the vortex which will lead to the next level. The levels are the green boxes which represent grass