For you, who like to create art & that have access to Photoshop, I think I have found a easy way to emulate the painterly style we see on the demos or for the cut scenes. You do not need a new version of PS. I use an old CS2 and I think that that brush should still be available in the latest versions.
1. Open up a picture (which will be put in your background) and create a new layer (which is names Ebene 1 in my German version)
2. Select the rough water colour brush almost at the bottom of all the available brushes in the drop down menu. This one has 100 pixel. Choose a pure white as your colour.
3. Paint with rough strokes at 100% opacity around your motive from the inside to the edges.
4. Turn down the opacity to around 40% to add a few strokes with a very watery colour
3 minutes of work, with a pretty good effect.