I don't agree completely @mijostyn. There are some serious speaker placement issues, but one advantage of the room being small, is the nodes are all higher in frequency so smaller treatments, and the near cube means the nodes concentrate at the same frequencies, worse if untreated, but easier to treat.
The main thing here is some heavy duty absorbers on the front walls in front of the speakers, and then some heavy duty absorbers behind the listening position. This will allow a lot more flexibility in placement and seating. Hang some heavy panels from the sealing, and standard carper will be fine. 2 or 4 small subs.
It would not be my first choice, but you work with what you have and you use a method that suits the room.