Sonic and All-Stars Racings Transformed is a racing game developed by Sumo Digital and published by Sega in 2012. I actually think this game is fairly understated. I actually really enjoy playing this game for a few minutes at a time. I even suggest playing it Locally with friends every now and then. The main difference from Mario Kart is the vehicle transformations your ride can do. In Sonic and All-Stars you'll sometimes have to speed across water and fly through the air as well as travel on the ground.
Sonic and All-Stars uses a lot of "shiny" textures in its text and panels. Much of the UI is silver and blue (probably to stay in-line with the Sonic brand). The flow to start a match is a little extensive with lots of clicking through menus. But it keeps the information to a minimum. There's a lot of screens I would design differently too. The floating islands are a cool addition but they take up half the screen. There's also control problems when it comes to the menus too (for instance: you think to press A to focus on a settings option. But instead, it saves your settings and exits).