Hi Bernd... not sure how I missed your thread as well!
Old - lovely colours and nicely processed to get the most out of those blues. Perfectly on theme and well captured.
Metal - certainly is, but I find the bright overhead sun a bit harsh on this one. Perhaps zooming in to a section of roof and making more of those alternating columns of highlight and shadow? Good spot though and I think there's an even stronger picture in that subject to come
Captive - love it. I genuinely wouldn't change a thing about this shot because as far as street photography goes, it works for me. It's even better (unusually) for the lack of eye contact as it tells more of a story to me. Super spot and perfectly on theme.
Miniature - a good idea and solid composition. I kind of wonder if it's lacking a touch of sharpness on the nearest figure, but it might just be the way it's uploaded to the forum?
Happy - Not my favourite, I'm afraid. Given the quality of your earlier shots, I hope you don't mind my critiquing this: wonky horizon, exact mid-placement between the two trees and side on profile instead of more face-on all weaken the shot for me. Also, DOF choice leads your eye to wander around rather than focus in on the subject (also not helped by the face being turned away). I think the same idea could work well, but might need those sorts of adjustments to really make it sing for me. Sorry!
Abandoned - nice take. I like the green on green and the composition works really well, together with DOF choice. Is that a slightly wonky horizon I spot again, though
Some super snaps there and very much looking forward to more! Hope you don't mind my harsher crit on Happy - the rest are top drawer