I've noticed that a sizable chunk of new players only play for a few days and then abandon the game, or just get booted in the first few turns. Daily rewards can urge players to log in more frequently and daily, which can slightly reduce the number of boots in the first couple of turns.

The rewards can range from points to use of level-locked features for an amount of time. For example, a Level 20 player logging in for the fifth day, can use the gift card in the next game he hosts or when a player logs in for a week straight, he can gain access to a map requiring a high level like China. Players that have already unlocked everything could get points instead or the use of, for example, the bomb card in a single game.

Daily challenges will be real-time games on a random map with semi-random settings and a random amount of AIs. The game can only be played by a player once per day and the number of turns it took to win will be added to a daily leaderboard. This could introduce new players to a variety of maps and encourage freuent log-ins.