There's a paid version and the free version is locked to 30fps? I also see on CryZENx says on their Patreon that "Patreons will have 60fps option aswell". Does "paid version" mean "the version that Patreon patrons get?" Does it go back to 30fps if you cancel your Patreon subscription?
Whatever the case, basically DRM. Pretty shitty and very much turns me off of that whole project. If he'd make it FOSS with an intrusive splash screen asking for money every time the game starts, that'd be far preferable to this. (Hell, even if he didn't make it FOSS, 60fps for everyone with a beg screen would be preferable to this. Still not the sort of thing I'd touch with a 10-foot pole, but a little better at least.)
But even aside from that, I can't imagine Nintendo will let CryZENx continue this project for much longer. There are so many examples of fan projects that have been shut down.