The animations would greatly benefit from either a voiced over narrative, or a side text block that explains some of the important aspects of the stereochemistry of reactions. For example, in the SN2 reaction, there is indication of 3 different R groups, but no indication as to inversion of configuration. This is also the case with regiochemistry of the epoxide ring opening reactions. For a student just learning these reactions, there is not a readily apparent reason why bases attack the less substituted carbon and under acid conditions the nucleophile comes in at the more substituted carbon. One other aspect of the acid ring opening that can be confusing it the statement that enantiomers can be formed. It would be very beneficial to have two different colored arrows showing attack of the carbocation from top or bottom and the resultant enantiomeric products in similar colors. I also think the SN1 could be improved by reversing the first and second slide in the sequence. By showing partial charges on the bromine and carbon in the initial slide, it would help students to understand why the bromine leaves and give a reason for the curved arrow. One other aspect lacking is lone pairs of electrons.
The animations played smoothly and did not have any problems. There could be an explanation of the green button can be used to show the entire mechanism without pausing between slides.