It's a fun game but it's a clear cash grab on the Mario series. A lot of assets from NSMB, NSMB Wii and even Super Mario 3D Land were often reused in this game like most of the OST, the sound effects, the voicelines, some level ideas and some boss fights that they completely recycled like the Final Boss..Twice. It really comes off as lazy sometimes especially since the only new thing to explore the levels with is the Golden Flower.
It's certainly one of the easiest 2D Mario games out there too. Same for the 100%. You will definitely need a guide for some Star Coins & Secret Exits though lol.
While you will not have a bad time with this game, it's inferior to the previous two games by a wide margin.