I initially played this game on the XBox Game Pass, and went up to the Mystical Workshop. I bought it back recently on Steam, after it got out of the Pass.
This is a very enjoyable game, very well thought through. It is a mix of platforming, monster collection, strategy, duels, and secret hunting. All is very well balanced, and you'll find yourself wanting more. All the monsters have their own capabilities, and an extensive list of skills. You'll have to find the best synergies that work out for you and for specific encounters. I've never found myself completely stalled, and there's always a challenge you'll want to overcome.
Secret hunting is fun, too, and requires you to look for special abilities from monsters (destroying secret walls, levitating, grappling, orbs activation, etc) to hunt for chest and more. There's also some tinkering as you'll be able to upgrade the equipment for your monsters. Light- and dark-shifting of monsters allows to to find even more synergies and strategies.
Musics are also a plus. Without being exceptional, they are good enough to keep you entertained all the time. Graphics are cute, too.
Very good game, you'll not be disappointed !