maybe a co-op mode or a 1v1! both sound great and challenging. perhaps the co-op mode could have specific criteria for the words accepted such as "no longer than 6 letters" "ends in -ly" etc. so it could add a layer to challenge and force the players to brainstorm together. for the versus mode i imagine a console-like split screen with both players competing for the highest score or the usual single-player screen, except on the top right side of your view you have your adversary's score, number of attempts and a timer for the current attempt.