I keep wanting to write about the Disgaea gacha but I keep forgetting, which is pretty much the most appropriate thing I can say about it. The game is really forgettable and is just a cookie cutter gacha - The gameplay is vanilla turn based rpg, and you mainly grind for shit. You'd think it will be the tactics gameplay the series is known for, and I'd wager that's what NIS originally tried and it failed to capture a player base since you can't make a gacha require thought.
Besides that you just roll for characters, but there is no real synergy between characters and you'd do best just putting your biggest beatsticks in your party. Rarity is incredibly important and while you can increase character rarity, I don't care enough to actually grind some junk character to check if it compete with main characters.
Another problem in the game is that if you played the games then you already know all the characters, so there's not a lot of reason to look forward for any specific character, though on the other hand it's nice to see the old cast interacting.
Finally, at least where I got to before I lost interest, equipment is pointless since leveling up is far more important than gear.
The one very nice thing I will say about the game is that it's far more lenient and simple in leveling up characters and you get a daily roll. But the pricing is absolutely insane.