Ignore that childish one-star review. Don't take my word for it; note that the Globe and Mail newspaper gave it 3.5/4 stars.
Rihanna, whether you like her hyper-sexualized presentation -- as a guy, I find it often over the top, hence "unsexy" sometimes (ladies, you cannot "overpower" men with sexuality -- well, okay some guys will go for it, but not decent guys) -- is quite talented, if not quite up there with Madonna, Whitney, and Beyonce (yet).
Moreover, her (or her producer's) music selections are fairly imaginative in terms of song-writing, rhythms, and arrangements.
Yes, some of the lyrics delve into dark areas (e.g., masochism), but overall the direction is positive -- and I hate this word, but "empowering".
Mostly, the disc is enjoyable, rhythmic, fresh pop/dance/R&B music, with some edge.