Moi Rai Games and Team17 Digital Ltd have released Monster Sanctuary in Early Access with Linux support.
Following a successful Kickstarter, Moi Rai Games have blended a few different experiences together in Monster Sanctuary. It has the exploration and adventuring found in metroidvania-like titles, with creature catching and combat that Pokemon made popular. It looks great too, take a look:
No thoughts as of yet, as we're currently still waiting on the publisher (Team17) to let us know if we're getting a review key or not.
Currently, they plan to remain in Early Access for at least a year. During this time they will be adding in additional monsters, new areas to explore, an improved skill tree and whatever else they come up with and decide based on feedback. The price may change as more is added but they haven't confirmed yet if they will raise it or not.