This is a good choice for a full meal, a between-meals snack or a Happy Hour draft beer. El Mundo's menu has mostly Western choices, and everything I've ordered has been prepared nicely. Friendly staff, although the staff turnover has been fairly high through the years I've been coming here. Nice river views from the outside tables, though expect to be bothered by the never-ending procession of touts, beggars and such. Prices are in-line with nearby restaurants. Highly recommended.
A word about Riverside street beggars. Begging on Sisowath Quay, the main Riverside street, is mostly a scam. You may see weary-looking women carrying infants or toddlers. Don't assume the young child belongs to the woman -- there are many "rent-a-babies," provided for a fee, that these women carry as stage prop's to make their begging more believable and effective. I'm told the children are given medicine to make them quiet and docile, more-or-less tranquilized. Begging is a business, and good-hearted tourists are played for suckers.
I've also seen men dress up as Buddhist monks and carry a photocopied document of some sort "proving" they are working for a bona fide charity. Totally a lie, of course -- they're also after your money. Be smart and give to an NGO or charity you are familiar with.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.