I've found this Melvor-like on Steam and it looks better than most. It has an upfront cost, but seems well polished and has an active developer.

It's like Melvor in many ways, but I wouldn't call it a clone either. It has its own take on pretty much every mechanic. For example, it also includes a prestige mechanic for the individual skills.

The only negative reviews I've seen so far are that it's "like Melvor", which while true is kind of an odd reason to leave a negative review? It's not exactly hidden what the game is like.

Oh, and while it only marks Windows as supported, I'm currently playing on Linux.