So here is a list of the stores that I visited!
Comics Hutterer, Rotenturmstraße
Müller seemed to be a random store with a bunch of stuff and they had everything from candy, make up, stationary and of course toys! They had a large and nice selection of toys, train sets and games. The Lego section was one of the largest and while different toy brands did not have large sections they had a a bunch of brands and toys instead, which is also nice!
Thalia is a super awesome and well stoked bookstore! They do have some toys, some Lego and random stuff, but if you want a book this is the place to go! You might notice that the lovely people of Austria produce and translate everything into german, that include tv shows, movies ( they do have a english cinema quite close to the center if you feel like seeing a movie on your trip) and of course books! The best part of Thalia, for me as a foreigner, is there English section which is large enough to be divided into smaller section like Fantasy and so on.
Donau Zentrum is a large shopping center with a few really nice toy stores. You can get there buy train, or taxi, in just a few minutes.
Elbenwald is a super neardy and awesome store that has collectables, shirts and a bunch of random stuff. They have divided there store sections after fandom wich is super neat. In the photo above you can se the Star Wars section, but they also had one for a bunch other like Harry Potter, Doctor Who, DC, Marvel and some smaller section with One Piece and Supernatural for example.
Fische Spielwaren is a typical toy store, it is not the largest store but a good size with a good selection of toys. They had all the standard toys like Lego, Barbie, Playmobil and so on. They also had a nice selection of Sylvanian Families.
Lego Store, what is there to say? Lego stores are always awesome! This one had a nice layout with a lot of light and open space. The staff seemed nice and they have quite a large Pick a Brick wall. It was much bigger than the one we have here is Stockholm which was neat.
They also had a Game Stop with a very small loot section but a bunch of games and a Müller which a large toy section and nice toy selection.