I've linked 3 islands so far and almost stopped after the first one. The preview made it look like super mario rpg (which I loved and bought and beat the remake). And while they take the battle style from that, this is the only part. The game is very slow story wise and repetitive in every way. There is a ton of dialogue scenes that repeats itself and you have to continually press buttons to skip it (button pressing). We know story has never been a mario game strong point so I don't understand spending so much time on it. It also hand walks you through everything like it's made for a 5 year old. Though it has light puzzles there is very little for you to figure out as everything is handed to you.
Then the actual battles. It's like rpg in that you take turns, you can block and even counter when attacked. The disappointing part is when you attack. You can hit buttons at the right time to up your hits but each and every attack requires 3+ buttons at the right time (more button pressing). Or else you barely do any damage. Then you have to switch which button order depending if luigi or mario is attacking. Which means hitting buttons through the whole battle in the right sequence and sometimes getting mixed up on luigi and not getting much damage. And the same when dodging or countering. Hit buttons at right time and switch which button you hit. Very repetitive, very boring, very tiring for your right hand.
Beat the first boss and that added a little extra button presses at the right time to do extra damage to him. Then I unlocked the brothership attack and it's MORE button pressing. Something like 5 or more button presses for the attack (at the right time) and it didn't appear to do anymore damage. This gets tiring fast and takes much longer for battles.
It has an equip system like mario rpg and that seems well made. They get xp and level up and every 7 levels you get to choose an extra bonus (vs every level). It's less customizable but makes sense to have st strengths for the characters. I was hoping we would get other players but so far not. It is after all "mario & luigi brothership". Which sadly ads to the repetitiveness. They have side quests which so far has been very easy though a bit time consuming having to travel back over all the maps (islands) again. But don't worry they mark where everything is so you don't have to search for anything.
So in summary it could have been a great game but the battle system was not done well. They took a great rpg system and ruined it with having to time EVERYTHING and press buttons non stop instead of being able to choose your attack and enjoy the battles or do an extra strong attack with a single button press if you choose. They tried to focus more on story but the characters are constantly repeating themselves and giving long pauses. Going to try and play it through to see what else it brings....