The Aquamarina Beach Hotel is an all-inclusive (food, drinks, on-site activities) hotel located on the northern part of the hotel strip (east of downtown), on the Gulf of Mexico side of Cancun. It's fairly small and definitely a budget hotel. You don't pay much, but you don't get much either.
The rooms are small, but clean, with balconies (at least the ones we had). The bathroom only had a shower (no bathtub), and the in-room "safe" was a bit of a joke. The pool is small and only really suited to playing water volleyball or lounging. The two Jacuzzis on the deck tended to be lukewarm. The beach area adjoining the hotel is good.
Lunch is generally pretty low-quality, consisting of hot dogs, hamburgers, or pasta. Dinner is generally better but is still at the level of diner food.
The people who work there are polite, friendly, and helpful, and service was decent.
The evening "shows" are pretty cheesy, although the young group of people who work there try very hard.
If you need a place to sleep and don't care a whole lot about facilities and food, this place is a good deal. I'd be interested in trying out other hotels before returning to this one.