Move with the on-screen buttons. Hold X to restart. To copy a block, press "O" to switch to "Copy Mode." While in this mode, use the Arrow Keys to highlight an adjacent block. When you've highlighted the block you want to copy, press "O" again to change your character into that block. If you have formed a line of three or more blocks, those blocks will be destroyed.

TIP: Think carefully about which blocks to destroy first, because you could get stuck.