Do you like Sonic? How about Tetris? If both these games are up your alley, you'll have a great time with Sonic Blox.
Many games that add their own twist to Tetris don't do a lot to actually change the game. At first, this version of Tetris may seem the same. You'll see one block falling at a time. You can move each block to the right or left with the corresponding arrow key. You can also rotate the block by pressing the up arrow. When you have a block exactly how you want it, you can send it to the bottom with the down arrow.
What makes this version unique is Dr. Robotnik is trying to get in your way. He periodically flies across the screen and sends missiles down at your blocks!