I think its great fun with 2 players myself. The obstacles are tricky enough with 2 players as well if you want to get 3 stars. I'm sure if you are really good at it then its not easy but we make enough mistakes that 3 stars is at least some effort
Have you played it 4 players? I've triple starred it with my wife in 2 player mode and with friends + wife in 4 player mode. In 2 player mode it's a bit of a joke as they give you such a low score target that you lose all of the pressure and therefore excitement that 4 player mode gives you.
They didn't have much choice though because it's a party game balanced for 4 players. The whole point is to get in each others way and to have all 4 people occupied and constantly changing roles but there's just no way it could work in 2 player mode without losing a significant part of what makes the game brilliant.
Missing a triple star by one point because the roles changed and 3 players tried to get through the same choke point at once to block the final delivery by 2cm had everyone in the room screaming at each other. The closest we got in 2 players was getting frustrated because the rooms rotated and we got blocked out of an entire section for 30 seconds. We still triple starred that level.
Can you play 2v2? That might be an interesting one as well! Either split into couples or men vs. women!
There's a dedicated 2v2 mode which is a lot of fun! I think they should have had the kitchens from the 2v2 mode for when people play as only 2 players as it works a lot better than the 4 player kitchens.