We stayed in the NinjaGo district, of course the hotel and room are a kid's dream. We liked the decorations and the small game to find the treasure in the room. The room's size is decent, I thought the room was actually larger, especially the kid's room.
I did not like the mattresses (too soft) and the pillows (but I also understand this is my personal opinion), and I would have add a mosquito net at the window, since the room is near a pond and it could be that mosquito or flies are coming in the room.
Overall, it was a super nice experience, there are a lot of playground for kids to play and also some good alternatives for dinner.
Breakfast (included in my rate) was really good and the staff was super helpful and nice.
We were there during the week, so maybe during the weekend and during the summer holidays, so for us there were no problems at all with overcrowding or anything else.
Parking is also really close to the hotel and the reception's staff was nice and helpful.

We stayed on ninjago, very lovely. The detalis are very nice. You must eat at hungry bear restaurant - you have lots to choose, many side dishes, stuff is amazingly friendly and food super. You have a place to play for kids.

We stayed here during the Easter holidays and it was really lovely. We had a room in the castle and we could see the park from our room. The kids enjoyed having their own little room in the front. The room was clean and so was the bathroom. The shower is with a rain shower and they provide soap, but not conditioner, so bring your own if that’s important to you.

The whole village is really super for families, with playgrounds everywhere, mini golf (for an extra fee) and a high ropes course (also with a fee).

We had breakfast in the castle restaurant and dinners at the Jungle Buffet. I would say breakfast is pretty good, sometimes a little chaotic with so many people, but they do a good job of keeping things orderly. Also at the Jungle Buffet, we liked that the drinks are included and there was fairly okay variety for food options.

Some small details are a bit missing - for example the “treasure hunt” resulted in the wrong code, and this was not user error. The hunt was likely referencing a different Lego display than what was in the lobby. The towels could definitely use a little refresh, but they are still okay. At many other theme parks, when you stay at the associated hotel, you also get early entry into the park. This is not the case at LEGOLAND Germany.

All in all, I would most definitely recommend the LEGOLAND resort for families with children under 10.