Ok, but a bit uninspired.
Pinball games have always been one of my favorite arcade games. This one is actually pretty fun when you get it started, however the overall presentation will make you feel like something's missing.
First of all, I have to give some credit for using all the classic sonic pinball sounds. From the bumpers to the pads, it make me reminisce of Casino Nights. To be honest, there really isn't anything wrong with the game, but it could use a few additional options. The game itself is just pinball with a sonic theme. A good start but maybe adding some other elements could make it even better:
1. Giving the board a little more depth in the design. What you have so far is OK, but maybe adding a few more zones. Adding a top area to the board with a few other classic pinball elements that could make it that much more enticing to the player.
2. As much as I like the design of the board, an option to change the skin of the board would be cool. Perhaps making the background like the classic Casino Nights stage or even Sonic Spinball.
Other than these suggestions, the game itself is still a rather enjoyable standalone. Although feeling somewhat stripped, this could be just what you need when you have nothing planned for a day.