The unbearably cute plays/concerts that the students put on is one of my favourite things. There are additional modules like Handwriting without tears that provide further opportunities for enrichment. We have not participated in these modular afternoon programs because of scheduling conflicts with naps, but I love the idea of them. There are a couple field trips for the older kids.
Tons of great extracurricular options, as well as half-day options at certain levels, french immersion afternoons at certain levels, and more. See my notes in the Academics category regarding development of well-rounded students - I think that is one of the things this school does the best. Regarding competitive extracurriculars, that's one where I'd say I don't recall every seeing something like that. They are too young to be competitive and I suspect that question was more intended for reviews of the grade school level.
As a preschool, we weren't expecting a lot of extracurricular activities from Children's Garden Nursery School and were more focused on socialization. That said, the school does provide afternoon modular programs that further develop academic skills such as reading, arts and crafts, and writing. We enrolled our daughter in a program called Alpha-Mania which is a once a week program for a few hours that fosters pre-reading skills through dynamic themes, interactive play, and multi-sensory activities. The classes sizes are small this year (2 to 3 students) so our daughter is getting a lot of attention. The results are clear: our daughter is a little over three and is able to recognize all the letters and spell virtually every word presented to her.