I have been a student at CSU since 2011 till 2013. One of my favorite places at this University were Theatre department, Library (is huge - go to the top floor and read your books there, then relax and look at the beautiful view outside), and of course - the Rec Center! I would say this rec center had almost everything you need (the only things I wish they add are sauna and jacuzzi). You want to play indoor soccer - not a problem, basketball - use 3 courts on the second floor, volleyball - please feel free to join. If you love to lift some weights - there is a third floor which has a dedicated space for that. After my workouts, I loved to go to a swimming pool.
This Rec Center is definitely something I miss. I wish I lived closer to Downtown and in that case, I would definitely buy a pass to this fitness center.
GO VIKINGS!!!