Selection Sort, for example, makes the algorithm look extremely (impossibly) good at first glance - O(n) - because it's not showing the majority of the steps.

Instead of

    for (var j = i + 1; j < D.length; j++) {
        if (D[j] < D[minJ]) {
            tracer._select(j);
            minJ = j;
            tracer._deselect(j);
        }
    }

it has to be more like

    for (var j = i + 1; j < D.length; j++) {
        tracer._select(j);
        if (D[j] < D[minJ]) {
            minJ = j;
        }
        tracer._deselect(j);
    }

Bubble Sort has the same problem, as do Quicksort and Mergesort.

Normally I wouldn't mind, as showing time complexity is probably not the scope of these examples or your visualization, but the examples suggest that this is intended for beginners, and it might give them a false sense of the time complexity of these basic algorithms.

By the way, I really like the visualization, I think it could be quite helpful to aid teaching about algorithms.