Okay I'll try to bring in a more balanced argument than some of the posters on here.
In many ways this anonymous poster is right. Reputation and ranking wise - Greenwich falls near the bottom of the pile as a university. Correct me if im wrong but I don't think it breaks the top 80/90 on the Times or Independent rankings. The surrounding areas of Greenwich old town/Greenwich Park and Blackheath are quiet nice areas, but 5 minutes down the road each way and you're into the residental part of Greenwich or Deptford which are hardly as desirable. The campus is quite small although I think its spread around the area and they do have a medway campus as well but if a campus uni is your thing then Greenwich uni won't necessarily fill that criteria.
Employability wise in most subjects the name "Greenwich" doesn't carry much punch and within south-east London schools it's known as a bit of a dossy uni but as I've always believed once you leave university its entirely up to you what you do with your life and if you're someone that's incredibly committed, determined and hard-working, that will make up for the university's lack of standing as opposed to someone who comes out of a Leicester, Nottingham or Leeds and expects the world to fall at his feet simply because he went to a decent university.
I don't really know your academic/geographical situation (i.e. if you're a London native) but I'd say there are better options in an around London that are better academically/reputation wise but aren't impossible to get into. It all depends on your grades of course, but if you really like the look of Greenwich (visit id say) and the course seems good for you then by all means go for it.