The problem with Manila is that it got bombed out in WW2 and hasn't really recovered its pre-war charm.

The top experience of my out-of-town guests has always been the Intramuros walking tour given by Carlos Celdran. If you're even the least bit interested in the story of Manila and its people, I highly recommend this tour.

That tour will take care of one afternoon. What you do with the rest of your time depends on where your interests lie. Your hotel is smack in the middle of the business and shopping district so if shopping and dining are your thing, you won't need to go far at all.