Searching for a game
 

A few years ago I played a demo of a game that took place in an East European city. The game was supported by the local tourist bureau I believe. The graphics are based on real photos. The protagonist is mail. His grandfather(?) invented some sort of machine. You visit the local tourist shop a lot, and the protagonist likes the girl working there.

Does anyone know what I'm talking about?

It sounds like you're describing Yoomurjak's Ring. The main character Jonathan Hunt is the great-grandnephew (or was it great-grandson?) of Samuel Hunt from the AGON series (both were created by Private Moon Studios) and he explores the Hungarian town of Eger.

That's it :D

Thank you Trunkyo!