I am moving soon to Zurich and probably importing my car and personal effects in December.

I have collected and played computer games for over 20 years. Loads of games I would like to have shipped over (about 250->300) almost all 5->16 years old. Do I have to list every single title separately? I do not have purchase receipts as they were purchased ages ago. Is this also going to be a big issue?

I can see this turning into a nightmare.

Just list them as a box of video games and put a nominal value for the lot - and state that they are over 6 months old.