What I think is most interesting about this game is the Mission mode. Similar to Generations console, you can unlock museum collectables by clearing missions. However, I would not advise that anyone bothers to try to complete all of these missions unless they're playing on a hacked 3DS or and emulator because of the 100 missions in the game, 9 are locked behind story progression and the remaining 91 must be purchase with 5 3DS Play Coins.
For the unitiated, 3DS Play Coins can only be obtained (without hacking) by stimulating the 3DS pedometer while the system is closed. There is nothing stopping you from closing the system and shaking it a bunch but let's pretend that you wanted to unlock all of the missions completely honestly. 1 Play Coin is generated by 100 real world steps. 455 coins (or 45,500 steps) are required to unlock every mission.
This website tells me that 45,500 would equate to aproximately 35.5 km/ 22 miles for the average man
(note that this distance would of course be shorter for a child that is playing this children's game but I highly doubt that anyone reading this is still in grade-school.)
However, the 3DS only allows you to generate up to 10 coins a day, so assuming that you walked with your 3DS for 10,000 steps each day, it would take you 46 days to legitimatly 100% this game. But what if you don't care about 100%ing the game by beating every mission? You just want the juicy collectable that's hidden behind each one. Should you choose, there is an option to instead of playing the missions (which this game isn't fun enough to justify doing), you can instead pay 5 more Play Coins to buy the collectable...except there are actually 11 missions that require you to spend 10 Play Coins to unlock their reward, so that's another 555 Play Coins. So, if for whatever reason, you'd gone to the effort of unlocking every mission but had no interest in playing them, it would take another 43.3 km / 27 miles of walking with your 3DS over 56 more days to unlock every collectable.
If you were to play the game this way, starting from right now, it would take you until 27th November to aquire every collectable. If you wanted to play the missions, it would only take you until 3rd October, with time to spare until Sonic X Shadow Generations releases.
Are any of you up to the challenge?