Since an entire section of the Stamps in mirai DX are dedicated solely to using the AR Theater, SEGA has downloadable paper cutout versions of the entire AR Card collection on the official website in case you got a regular edition or the digital version, just to make sure you can still get the Stamps.
The customisation is fun, with modules costumes and accessories for head, chest and back. For the Diva rooms, which might not be for everyone, you can design their room with furniture and shelf items and the vocaloids will sometimes interact.The reason is mostly the characters, they're all really loveable and cute.This enables players to hit and hold multiple notes simultaneously with a single button, which makes much of the game significantly easier.In Arcade and Mirai, a small chunk of your Life Meter is protected by a "Safety" guard for the first 30 seconds of the song, so even if you struggle with the chart you won't immediately go from loading screen to Game Over.All the Worlds Are a Stage: A lot of Arcade-exclusive songs use multiple existing stages as well for their videos, due to being produced in Edit Mode. This song alone should come with a seizure warning installed.
An Interior Designer Is You: In all the games except the Arcade versions, there's the Diva Room, which lets you decorate the Vocaloids' rooms.
All Just a Dream: The Chance Time bonus video for "Kagerou Daze" features Miku waking up with a jump every time she dies, making it appear as her last failure was simply a dream.
The context of the original song says otherwise, though.
The latter two only have a couple of songs each though.
Alongside the main rhythm game, which is great on its own, is the character customisation and Diva rooms.