Cassette Beasts

An open-world monster-collecting RPG. Explore the new island of Willer, capture various monsters, record their abilities onto cartridges, and then transform into monsters for turn-based battles. The most unique feature is the ability to fuse two monsters into a brand-new form, and you can also use monster abilities to explore the map and solve puzzles. The full version is available on Steam, so if you want to experience it, it's best to buy the PC version.

Just that the content is a bit lacking