$2.99 for iPhone/iPad 3 stars A lot of mashups in popular media simply don't work ("Aliens vs. Predator" anyone?), so it's surprising that a game that fuses the classic board games Risk and Scrabble seems like such a natural fit. That's exactly the case with "Quarrel"--in which players conquer the enemy not by lucky die rolls but by spelling out the highest scoring word possible with letter tiles. "Quarrel" sorely lacks a multiplayer component, but the rest of the game is so addictive, Alec Baldwin might get kicked off another plane if he discovers it.