If you're using a tablet with Android, maybe you haven't installed Flash? Most content here is still in Flash. I don't get why Adobe officially dropped support for it on Android, but plenty of the popular browsers (like FireFox) do still support the plugin if you manually install it. Adobe have some instructions for it here. You could also install a browser with Flash built-in, like Now Browser. Running submissions using Unity might be a bit more difficult, I have no idea how that'd work on a tablet, but considering Unity games can be pretty slow even on a regular computer I assume they might not work at all. There some HTML5 content too, but it's still pretty rare; not possible to filter out from other content forms.
Hope that helps? I had some Internet trouble for a while, had to resort to my cellphone to reach the site, and though it really isn't optimized for mobile overall (filling in forms was probably the hardest part), watching the content was no problem at all. Just took a little longer to load.