Explainer video with animation

I want to promote the website [login to view URL] (it is a currently inactive yet safe site, you can visit it without worries; it is just that its certificate has expired and needs renewal after we are done here). This promotion will be accomplished through a short video that will show how [login to view URL] works and what it is. Hence it is mostly 'filming' and editing; no need for extensive 2D animation or anything, since the website's intro that features animation has already been produced and will be 'linked' with this short explainer video that we will produce now. Nevertheless, good knowledge of 2D animation and/or video effects etc (like for instance those in [login to view URL] or others) is highly desirable. So, to sum it up: this last part of the video will mostly show how the subscription process works and how the games are played, how users get ranked based on their scores etc, as if there was a screen-capturing software 'taping' some user browsing through the website and playing the games. I will provide detailed script (and even templates, from our graphic designers!) on how this will unfold. A native British or American narrator will be used. I will provide the text of course. Duration of the video: not more than 20 seconds. Actually, the shorter and more comprehensive the presentation, the better. Please include samples of your work on this field.