Being required to perform repetitive and tedious tasks to advance.
"Anything above the very early levels require several hours to level up and unlock new content"
"[ikan] [Minor] You need to play songs to level up (referred as "sphere" ingame). You also need to grind a bit Lumina to explore the Sphere Map to unlock a couple songs. This is pretty good for rhythm games since you'll be playing a lot if you suck, so nothing too surprising here. It's also pretty easy to grind Lumina if you have good-enough skills."
"Some of the achievements in the game require multiple runs and aren't always in the player's best interest. There's also the cars, some of which require a lot of in-game currency to purchase, and the maps, which require hundreds of playthroughs to unlock all of them."
"Must collect lots of parts to upgrade the car. Only certain races have the part you want."
"re-play levels to collect coins that you van use to upgrade the Kitchen and decorations , else it's impossible to pass levels, also events with limited time that if you lose, you have to start from scratch or pay to buy gems and coins to keep your current score(if you don't have any), read under daily rewards too"