A two month sprint I worked through to try my hand at Metroid-Vania. The design documents are included with the source and it was genuinely fun to make but I don't have plans to continue developement on it. If you've found your way here, give it a shot! It's not gonna change the world but it's a pretty fun short story.
I attempted to build for web but the controls are pretty intensive and the web build would require a pretty hefty rework that I don't think many people would get use of so as of now it's install only but you're welcome to grab the files and try to build for any platform you'd like! Happy coding!