Thanks for your interest. Added platformer tag, and is also tagged fps-platformer.
No, sorry, I mean computing platform. The operating system. The Itch desktop app doesn't let you download a game if your platform/OS isn't listed in the Platform field. For example, https://girlsmakegames.itch.io/blubblub has "Platforms Windows, macOS" in it's More Information box. Because that's there I can download the game through the Itch app.