Duelle is certainly bound to be interesting for most Rivette fans; seeing his take on a shorter, more "action" based movie interested me quite a lot at least, and outside the bounds of Rivette's work, Duelle is very unique and interesting by itself as a movie.
Overall, the characters and atmosphere are created very well, and the movie doesn't drag at all, in my opinion. That said, it does feel like the movie is lacking something that would make it stand out or leave a strong lasting impression.
If I had to guess, it would be, for me, that the goddesses don't have much more motivation than 'staying on earth' and that motive isn't given much depth throughout the movie. I also think that the sudden shift around the one hour mark with the two goddesses facing off was done well, but the movie up until then didn't flesh out some of the characters well enough for the movie to pivot in the way it did without friction.
Overall, I like it, and I would recommend watching it, but it doesn't dazzle me all around.