ALDI Talk is less restrictive than the traditional prepaid SIMs. You only have to pay for the SIM (at least this was the case when I got one for my dad) at the checkout lane at any ALDI store and you can easily register the SIM online.
If I recall correctly you can use a German hotel address. If not, try using a friend's address if they have one here in Germany.
https://www.medionmobile.de/merit/registernew.do