Yeah I experienced the same thing. I kinda figured if I scored zero it might just skip to a "you won" screen and it didnt. Not sure whats left after acheiving 0.
The idea is you want to try score as many points as possible without ever beating your previous rounds score. This isn't explained too well though unfortunately.
You want to score as high as possible in the first round and then aim to score high but not quite as high in the next round. Then keep doing that until you eventually lose