Just platinumed it :lol
In retrospect I feel my early impressions (see
this post) were a bit too harsh, although the critique is still valid in my opinion.
When I did my second playthrough the game redeemed itself. I complained about the slow response of the Prince (I wasn't used to the controls yet) and the sucky battle system, but it seems I wasn't in the "PoP-flow" yet, if you know what I mean. On my second run (with Ezio costume of course) I skipped all the battles I could skip (about 90% of them, I was maxed out already), and the flow of the game was 1000x better, hopping from one end of the castle to the other in no time. I finished my second run in about 3 hours, which was perfect. Once I got into that flow when you can clear all obstacles in one fluid run, the authentic PoP feeling clicked and a smile appeared on my face.
I strongly recommend everybody to do a second playthrough like this, it makes the game feel so much more rewarding. :lol