There were plenty of activities that came with the housing. I made many local friends and they also invited me to several activities.
There were many different sports that you could go to for free at campus. There were many gyms, many swimming pools in really close proximity were you could go for free.
Student life wise - there were many parties. Women could get drinks and go in to clubs for free every Wednesday. I am not a party-person so I did not have use for this, but many of my friends appreciated this.
By living on campus it is easy to make many friends. Also, the facebook group for foreigners arranged a lot of different activities so you were never really left alone.
My impression of Signaporeans is that they are very active people. They play sports until 2am at campus. There is always something to do, and you are welcome to join any activity.