Puntarenas, Costa Rica - any chance of seeing a sloth?

Were here in January last time on a cruise. Went to Carara National Park but really disappointed by lack of wildlife...just leafcutter ants. Is there any chance of seeing a sloth? We're going November this time.

Has anyone tried NCL excursions Scarlet Macaws Sanctuary & Puntarenas Sightseeing OR Aerial Tram & Rainforest Adventure OR Botanical Gardens Pura Vida?

Any recommendations/highlights?

We did the aerial tram and saw one sloth in a tree. They had snakes in glass cages at the valley station. We saw crocodiles in the river but only out of the bus window. The bus slowed down for us. We also saw monkeys, again out of the bus window. I was disappointed in the lack of wildlife.