Most of the tasks are really easy. Of course, for fulfilling some missions you will have to devote more time, for example, to play 700 poker hands  at the Rush&Cash tables. Such tasks, however, do not seem impossible.
In fact, you may encounter difficulties only with completing challenges like “winning a tournament from the Bounty Hunters series” or “hitting the jackpot in All-In Or Fold”, and in case of failure, you will not be able to get all $350 stated in the promo. But even without these missions, T$ and real money you can earn from simple tasks seem a sizable increase to your bankroll.