Currently, I think they are used so you can see if there's something specifac that you want in a game while just browsing through.
Of course, with the current setting, it gets annoying to click the game, look at the tag, and then find that there's not the tag that you want.
Which is probably why there is this! Click render 2 - click 'Play' - take a look at what's there. :) Tags are quite useful there for just browsing through.