Alexei Pajitnov has a lot to answer for. This Xbox Live Arcade puzzler owes a great deal to Tetris but has enough little crinkles and quirks of its own. By now you’ll know the score with this type of game. Tiqal works like Tetris in reverse, in that you have a grid of pre-laid blocks, with more blocks dropped in from the top of the screen. The idea is to make a cluster...