Oh, Alex, I hope you keep waking up for years to come so you'll be ecstatic when you're 80!
Fewaz, as TropicAlex mentioned, your definition of "fun" is key. There are plenty of bars in Tana, but you'll need some French, at least. Good music is plentiful. There is a zoo which, while not exquisite, is a decent enough "natural" place to wander around on the weekends. The market in Soarano can be a distraction (but watch your wallet!). There are a couple of places in Analakely where you can watch football on a large screen on the weekends. Or you may dare to go to the stadium in Mahamasina to see a match, or find a basketball game.