This game is excellent. My very first video game was Pokemon Yellow Version, and I taught myself how to read so that I could play it as a little kid. I stuck with pokemon all the way through the 5th gen, but I got tired of the formula after that. This game did a great job of capitalizing on the elements of Pokemon that are good while breathing some much needed life into the monster collection genre. Firstly, while individual monsters have a sublevel that determines what moves the monsters learn, the overall level of the character determines the strength of every monster. In practice, you can switch between any monster and its stats will be on generally par with any other monster you might use, accounting for different stat scaling across monsters. Additionally, the moves you learn on one monster can be taken off and applied to other compatible monsters. The way the game handles levels made it feel worthwhile to actually get and transform ("evolve") every monster in the game. Additionally, the monsters have a chemistry mechanic where it is possible to make monsters change their types with some frequency. The dynamism made for really interesting battles. The shinies of the game also interplayed with the type switching, where shinies were not just a recolor, but were monsters with different types than their default types.
The last interesting battle mechanic is the ability to fuse. All battles are double battles, and you can fuse with your partner, which combines the stats of both monsters at the cost of only selecting one action per turn instead of two.

Next, you are free to explore the world at your own pace and in any order. It was nice to be let loose and go where was interesting. Additionally, the world was small enough that it never felt like an overwhelming task. There was always something to discover in every section of the world. It was a delight, especially when you add in the games excellent soundtrack. Shout outs to the forest track. It was my favorite. To compliment the exploration, I enjoyed the world's characters. They were not exceptionally deep, but they were appropriately developed given the scope of the game.

The game has a robust post-game, though by that point you will likely have explored the whole world. It becomes oriented around fetch-quest/battle a quota of monsters style tasks, though with some story development thrown in. Even if the post-game did not hold my attention as much as the main game, there was some thought and intrigue there that I can appreciate. Besides, after you beat the main game, you unlock Nuzlocke options and randomizer options that allow for another worthwhile playthrough.

On the whole, I strongly recommend this game to any monster collection fan. It was a delight start to finish with some interesting monster designs that sparked so much joy. It is still receives updates, and I expect to pick the game up again when the devs release another DLC.