The variety of ducks is great, particularly with all the DLCs installed. My personal favourite is the Shark Duck from the 'Duck Addiction' DLC and the unique sound it makes.
It's also a lot of fun to come up with all of the names for the ducks, especially when they're atrocious puns. :D
1,99€ for the base game and 1,99€ for each DLC pack, is a good price point in my opinion, especially if you are into weird and chill simulation games.
Other than that, there isn't much to say but, "how is a game about rubber duckies floating in pools (and not much else) so good?"
4.0