When you get to it, it is really a simple RPG. The dungeons and exploration are straightforward, the skills and weakness are simple, and you have a couple of minigames on top of it. However, it's one of those games where the whole is better than the sum of its parts, and boy is it better.
For starters, it really feels like a nostalgia trip, but in a good way. You get that vibe of exploration of a classic RPG (in my case, Pokemon Mistery Dungeon) in a fun and light package. The combat has some action like a Mario&Luigi game but the general strategy is not too complicated. Nothing feels too daunting or too boring and there is plenty of side stuff to do when you get to it. Also, the difficulty settings are really extensive so you can have a more challenging run if you want.
Now, the plot is really deceiving. Same as the Messenger, you think everything is going to be very simple and linear, you fulfill some big quest and that's it. But then it gets complicated, then more complicated, and then even more. The fact that a JRPG starts with such a chill vibe and then has these plotwists really turns the game for the better. In addition to this, I loved all the references to the Messenger (there are a lot), which made me like the plot even more.
My only nitpick was the ending, however, I just discovered there's a true ending which involves some sidequests that I plan to beat when they release the DLC because I'm too lazy and want to replay the game, so I can't say if it's good or not, but I trust it will.
Incredible game, incredible lore, would recommend.