Hi there! We are making a game, based in Chicago according to scenario, so I'm trying to find a high quality map of Chicago, any ideas would be appreciated.

What format of the map are you looking for, and for what use? Satellite image, roadmap, terrain height map, POI map, something else?

If you need the map data, look into OpenStreetMap and their API.

Some printable PDF map of Chicago, like this one, but free for downloading:

https://vectormap.info/product/chicago-city-map-vector