Every time you get to a new kingdom you're given 3 loot boxes. In order to actually play the game and earn moons for anything you do, you have to unlock the moon in a loot box. Each loot box gives between 3-7 moons, depending on the rarity of the loot box. You can get duplicates, which are sold for 1/10th of the price of the loot box in coins. The big grand moons that boss battles are behind are only dropped in the rarest tier of loot box. Loot boxes can be purchased starting at 100 coins for the cheapest, to 500 coins for the rarest. so the real world price is $1.00 and $5.00. There is also a separate set of loot boxes from which you receive the cosmetic items, which can be purchased through purple coins, but you can only get 2 per kingdom, there are duplicates, and you are not guaranteed to get everything with those two loot boxes. After you've spent your 100 purple coins, the only way to get everything is by spending money. Also whenever you die, an enemy in the world takes your lootbox and you have to track them down and capture them to get it back, but if you kill them before you capture them then the lootbox is gone forever. You also need to be always connected to the internet because there is an unskippable video ad before each loot box
This means that to complete the game, just beating bowser, requires opening around 200 loot boxes, and 100%ing the game requires closer to 400, depending on your luck. Cappy is also always encouraging you to purchase loot boxes with his large text box obscuring a third of the screen. There are also some enemies, especially after you reach New Donk City, that require upgrading your hat to capture, which is done by recycling loot boxes rather than opening them. This process adds a bit of XP to the cappy meter and spits out a few coins, it takes 5 loot boxes to level up Cappy, who has a max level of 5 which is necessary to beat the final final boss, Giant Mecha Tiara, who can only be fought upon reaching 200% completion after beating the full game with Mario and Wario, but each attempt requires filling the galactic readiness bar through either fully replaying the Moon Kingdom or by recycling Moon Kingdom loot boxes.
There is also a special bonus mission which can only be played by scanning a special amiibo, which is a real life rabbit with a cappy hat. The rabbit has to be purchased with the hat, is of super limited quantities, and preorders go up at 2AM only on Petsmart's website to shoppers with a Petsmart Plus subscription. This wouldn't be a big deal except that the bonus mission is bob-omb battlefield from mario 64. Amid the crazy fanbase, the amiibo cappy hat becomes literally worth its weight in gold and the rabbits are deified as holy beings. No journalists say anything bad about this because they all get a free pet rabbit out of it
But it's all ok because the lootbox opening animation is fantastic, showing a beautifully rendered magician's hat, with a funny animation of cappy reaching into it and pulling out all your winnings with a broodal or two. Players are upset, but it receives an 82 on Metacritic, and Nintendo overtakes Walmart as the world's largest company by revenue in 2018
