Toolbar on top. Edit BG toggles live cells (click). Create blocks: click once to begin a block, then click or drag over live cells to add/remove them from that block (click an already-selected cell to remove it). Press Create blocks again to finalize. Define Goal toggles hatched goal cells. Define target selects a block to be the mission target (it will get a bold offset outline). In Play mode drag a block orthogonally to move (Chunk mode allows moving touching blocks together).