Pretty fun and entertaining. It is unique that u defend 4 sides. As others have stated, it is a little lacking. Mabye more special blocks, like a speed block or a temperary barrier block or something. I like it though.
Oh, and by the way, my level code is: 0000000000000000000001100010001010111 0000101001000101010000001111010001010 1100000111101000101011000001010010001 0101000000110001110111011100000000000 0000000000000800080888088088080008080 8080808008008000808080888088088080008 8888080808008008800000000000000000000 0000000000000000000000000000000000000 0000