I just got this game recently and I was impressed. It plays like real arcade pinball with good physics, some nice tables, and a good amount of extras. Not only does it have a Sonic table, but it has tables based on Nights and Samba de Amigo too. My favorite is the Nights table and my least favorite is the Samba de Amigo, but they are all cool.
The Sonic and Nights tables have challenges, timed goals, and multiball just like real pinball. Samba de Amigo is a more simplistic design that has a good music based mini game and the ability to change the music.
The Casinoplis mini games are pinball based versions of slots, bingo, and roulette that are pretty fun. You can earn rings in these games to use in the chao mini game.
The chao mini game is a game where you raise cute creatures called chao. It's a virtual pet type thing. This game has a couple of cool mini games within the mini games. A matching game and a game where you try to eliminate colored balls.
As for as game modes there is arcade and story mode. Arcade mode is regular pinball and story mode is a mode where you try to beat challenges set by an oppoent.
This game also has multiplayer. I haven't tried out these modes, but they sound like they might be fun.
Unfortunetly, this game is currently only available at Target.