While I have visited Northeastern before, I was unable to get a feel of what the social life is genuinely like. I was wondering if anyone could answer what it’s like and if it’s a fun school. Although it isn’t the #1 factor for me, I am interested in going to a school that has a work hard, play hard attitude like myself!
I’d say the school would generally be this, though the play is different than what you may mean. Co-op and the city shape the social scene a lot - it tends to be more mature and less partying in my experience, but still very much a social and fun school. In terms of parties, the most common type is usually apartment parties (ranging from 5-30 people, depends on what you want / the night). But people go out and use the city all the time - concerts, city exploring, a good brunch/lunch/dinner with friends, all sorts of special events, a museum - you get the idea. I think that generally speaking, Northeastern students care about academics/career a good deal but are very much people who value the balance between work and social life. In some ways, I’d describe it as “work medium-hard play medium”. The work hard play hard idea to me always implied an always-on constant flurry of either social or academics, which implies a bit of being overwhelmed for me personally. Northeastern is very much socially about balance in all ways - academics, career, and social all put together.
As a city lover, I’ve had an amazing time here socially! 
But if you’re looking to go to a frat kegger every weekend, it’s going to be a different experience.
Hope that helps! Happy to answer any questions
^although there are frat parties (almost?) every weekend at NEU and nearby BU and MIT that many freshman partake in.