Cloudwalkers

Cloudwalkers is a short, fast-paced shooter platformer set high in the clouds. Across six levels, you can try to finish as quickly as possible or take your time shooting aliens to earn the most points. The game takes about 15 minutes to complete.

Your gun can overheat and kill you if you fire recklessly. You can compete with friends for the highest score or the best time. The game is open-source, so you can inspect and modify its code or use it as a framework for your own project.