Maybe I'm too harsh..
Maybe I'm too harsh, but it's just another tetris clone. Have we seen a tetris clone before? Yes. Many times. Many with more features than your version, such as previews of the upcoming block, a way to store a block for later, etc.
Basically, your game works, and it's okay, but I'm nailing you on creativity. You obviously have programming skill. Try creating your own game, and make it well. Or, if you must, take an existing game (like tetris), and make it your own. Change it. Make it better than the original, and different too.
Keep at it!