Fans of RTS won't be dissapointed at all with Mushroom Wars. Simple, addicting, and cheap!
The game has several single and multiplayer modes, which can keep you entertained for many hours. The single player campaign has about 30 maps, and you can select the game difficulty, so there is a lot of replay value here. There is no plot or story to be followed on this game, but it does not really matters, since you will be busy completing the specific objectives for each mission, which can require some skill to complete, especially the time-limited ones. There is also trophy support, for those who like to earn trophies for all of their games.
For a game this cheap, I don't regret at all getting this game. See you later, I'm going back to playing it :).