Brand New BTD5 Update – Daily Challenges! Log in each day and get access to a cool challenge – different modes, tracks, and restricted towers each day, but always a fun test of your skills. Beating it will win you Monkey Money and make progress against 4 new Achievements. Each Challenge is only available for 24 hours, and playing every day is the only way to beat them all. Daily Challenges require that you have all of the towers unlocked, so Log In, get to Rank 18, and play the Daily Challenge!