Bungalow floor plan, approx. 120 m²

Do you have side views and a site plan? The small windows next to the TV bench are a nice gimmick, but is the price/performance ratio worthwhile here? I like that you’re not sitting on the sofa with your back to the garden. The garden side is supposed to be the nicest part of the property, right? Maybe Leo could also have a window or even a door to the garden (yes, it needs to be locked for the first few years)? Access to almost all rooms through the open space is certainly not everyone’s cup of tea, but if it suits you, it’s definitely a good way to get the most out of 120m2. In the bedroom, I would either do without the "pseudo" walk-in closet or position it towards the bathroom. That would reduce some noise from the bathroom and possibly also allow for a window in the bedroom to the side, not directly facing the street.

Since I have known , I would always equip a bungalow with a fixed staircase. It doesn't have to be a space-consuming show staircase; 80 cm in width and a bit steeper is totally sufficient, but it shifts a lot of the storage space to the attic.

The bedroom is roughly square, so you can quickly calculate the "space" by the square meters... which results in 4.1 meters of wall length. That leaves about 1 meter for the dressing area. Anyone with an eye can see that there is no wardrobe with a depth of 60 cm drawn in there. So that’s not possible. Illusion.
The location of the bathroom is very unfortunate.
What do you do in family life when guests are over? Poor Leo, that’s all I have to say. He’s exposed to all the noises from the TV, evening visitors, and other activities.
A kitchen island would also be better, stretching it more horizontally rather than going deeper.
I find the bathroom unnecessarily big. I had a 2.20 x 2.50 m bathroom in a four-person terraced house. Ok, you don’t have to go that small, but 8 sqm is totally sufficient if you furnish it well (without a bathtub).
Our neighbor’s house was just sold with 119 sqm. But it was an L-shape. Our direct neighbors have 110 on a square... ok, both without a dressing room and without a third bedroom, so an office. Still, they have privacy, are modern, and feel spacious. Transferred to 120 sqm, there is always a game room left over.
Even with Danwood or Heinz von Heiden, I find more functional houses in the same size range.
But without a site plan... no cookies for poor me!

I really like the design right away with the large open living space with direct access to the rooms.
All the tips from the previous writers are super valuable. My two cents:

1. Reduce the bathroom size and use a space-saving staircase to the attic storage.
2. Give up the dressing corner in the bedroom for a more practical closet format.
3. Soundproof wall and door for Leo to reduce kitchen and living noise and plan sink / dishwasher / fridge as far as possible not on the “Leo wall.”
4. Garden access for Leo
5. Enlarge the wardrobe a bit and accept the “corner” in the “Näh-Zock-Büro.”
6. Enlarge the kitchen island a bit to gain more space next to the cooktop.

A bold floor plan with the central living area. It wouldn’t be mine. Above all, it bothers me that you can only get to the bathroom through the kitchen. While mom is making breakfast with the son, dad runs naked past the buffet. Hmm. When you’re young, that can whet your appetite, but the older you get....

Otherwise, I agree with those in favor of stairs to access the attic.

If it is bothersome, you can always put a large plant, shelf, or something similar there.

I really like the design at first glance with the large open living space with direct access to the rooms.

I do not like it at all - but I am glad that you like it and that you provide reasons or identify further potential for improvement.