It's the SUPER GUNBALL! You control a super-bouncy ball with a gun on its side. Shoot all the enemies and use special weapon pickups to get to the exit of each level in your journey to beat the bosses of that world. A and D (or Left/Right Arrows) to move sideways. SPACE or RMB to bounce off the ground. SPACE or RMB again just after landing will result in a higher bounce. LMB to shoot the current weapon at wherever the mouse is pointing. (Mouse cursor is transformed into crosshairs.) W (or Up Arrow) to use EXIT doors. This is actually the work-in-progress of the DEMO which will eventually lead to the FULL GAME with many more levels and worlds.
Here are some pics of prototype Gunball toys I put together as a concept for a Kickstarter reward.