Turbo-Beaver: That's not how it works.
Vronos: This workaround would not invalidate one’s right to a refund, especially not where I live.
With a couple of exceptions, why would it even matter where you live? If you think the laws of Germany would automatically apply, that's not the case. This is what you agreed to:
https://support.gog.com/hc/en-us/articles/212632089-GOG-User-Agreement 19.1 You and we agree that your use of GOG services and GOG content and this Agreement will be governed by and interpreted according to the laws of the Republic of Poland and that any dispute regarding this Agreement will be heard non-exclusively by the courts of the Republic of Poland.
And more importantly:
7.1. If you are a resident of the European Union or other applicable jurisdictions (excluding the USA), then you have the statutory right to withdraw from a purchase of GOG content within 14 days of your purchase, without giving a reason. However, this does not apply where you have expressly consented to the performance of the GOG content (which is digital content) beginning immediately upon conclusion of the purchase process and have acknowledged the loss of your withdrawal rights.
In any case, no need to prove anything to me, I don't care. I was just trying to save you the disappointment. You willingly entered a contract, and agreed to be bound by the user agreement. You might still get a refund if you do what you describe but it would be on compassionate grounds. Your best bet would be to say your computer is too crappy to run this game, and that you didn't know it in advance. But legally, you have no case here.
That is not to excuse the way retail PC pre-orders are being handled, which could have been better. But it was clear from the start that it was going to work like that. Some other solutions could include: (1) contacting the store to send you the code or the whole pre-order earlier, or (2) buying the game again on GOG, and gifting or selling the code from the physical pre-order to somebody else.