A charming and enjoyable RPG - heavily inspired by the original Paper Mario games - that is unfortunately inundated by bugs, lacking in polish, and contains a number of questionable battle mechanics.
Overall, the game is still fun - and if you just want to scratch that Paper Mario itch, then it's likely still worth your time.
However, with the current issues the game has, I don't feel like I can recommend it.
Bugs
The frequency at which I encountered these bugs are the main reason for this negative review.
Here's a list of all the bugs I remember personally experiencing:
unable to jump
unable to use the partner abilities
unable to swap partners
unable to move the cursor in the menu screen
the cursor going out of bounds in the menu screen and getting stuck
unable to scroll quest information in the menu screen
unable to talk to certain characters
unable to talk to the character that saves your game!
softlock due to being unable to end a conversation with an NPC
unable to complete a quest due to the softlock above
resting not healing all of your allies
healed allies remaining dead (with full health) upon entering battle
Luckily, sometimes these bugs are fixable by simply opening and closing the menu, or swapping to M&K, but often I have been forced to save and close the game. However, when one of the bugs is that you're unable to save... you can imagine how frustrating it can be to encounter them.
As I mentioned, the game itself is enjoyable, and perhaps you'll be luckier than me and not encounter as many bugs. However, repeatedly having to find a save point and close the game just to get the menu to work... well, this slowly chips away at that enjoyment.
I have also seen a number of comments mentioning that certain items are missing or specific achievements are unobtainable. This is annoying if you want to 100% the game, however, at least they don't directly impact your enjoyment while playing.
Polish
Obviously, this point ties in heavily with the previous bugs listed - never have I seen a menu screen in a game be so unreliable before. However, there are also a number of basic or QoL features missing from the game. These are obviously minor grievances, but their absence just makes me feel like the developers haven't played it themselves.
There are no keybindings to open specific menu screens.
Opening the map would commonly be done with the Back/Select button on a controller, but this is missing.
The D-Pad is entirely unused, but would have been convenient for quickly opening the weapons, consumables, boons, or party screens.
There is no sorting of menu items and quick scrolling is only added to certain pages.
Your weapons, consumables, and boons eventually become long lists, but with no way to sort them or jump to the bottom (where new items are automatically placed), so you have to hold down to scroll through them all.
The only page with some form of quick scrolling is the quest log, however, pressing up only jumps to the bottom of the visible list of items - and then you have to continue to hold down to scroll through the rest of them.
Finally, switching your partner in battle can only be done by Loaf - and it uses up your turn.
While I am fine with it using up your turn to swap partners, the fact that this can only be done by Loaf means that you always have to waste his turn in order to switch out your partner. I don't think it would really affect the difficulty by simply allowing your partner to use their own turn to swap to someone else.
Battle Mechanics
The main issue with the battle system is the Defend command.
Not only is it inconsistent in its usage, but it is also incredibly powerful and (if abused) ruins the balance of the game.
Defend allows you to gain WP (used for casting powerful attacks) by successfully defending against enemy attacks.
When you use the Defend command, it immediately becomes the enemy's turn and they attack the person defending.
This means that, if you defend with Loaf, the enemy gets two turns.
However, if you defend with your partner, the enemy only gets one turn - like normal.
I can only assume this is done on purpose, because the Defend command is so strong.
It allows you to continue using your most powerful attacks without needing to refill your WP with consumables. And not to mention the fact that later on you get a Boon that allows you to steal health from enemies whenever you successfully defend against their attacks.
Ultimately, this leads to the next problem with the Defend command: the safest and most effective way to win a battle (especially on the harder difficulty) is to attack with Loaf and have your partner repeatedly defend - allowing them to soak or blocks all of the damage, while also restoring your WP.
This is a singleplayer game, so you can obviously play whichever way you want - and I definitely wouldn't blame you for ignoring a complaint about balance. However, knowing that there's an easy way to win every battle did slightly ruin the enjoyment for me personally.
There are a couple of ways I can think of that this could be fixed:
Allowing you to swap positions would probably be the best way to solve this issue - there's no real reason why Loaf has to stand at the front - and this would open up other tactics like having your partner get hit so you can both attack.
Alternatively, if the enemies simply didn't attack immediately after pressing Defend, then this would allow you to switch it up by using Loaf to defend and freeing up your allies to attack. This wouldn't change how powerful the Defend command is, but it would make it less boring then repeatedly attacking with Loaf only.