I think that the Scirra Arcade does this quiet well already, also I will guarantee that some people will start complaining like:
"WHY DID MY 'FNAF4 FAN EXTREME REMAKE PART26' NOT GOT FEATURED ON THE PAGE!?!?!?"
I guess that the website will get a fresh look as soon as C3 comes out anyway.
Sure, the Scirra Arcade has awesome games in it, but the developers who want to make money out of their products won't upload their games there. I understand your point and your warning about possible issues, but I don't think that those can be fully hammered out. I think successful games should be on the showcase page based on their downloads, online plays or sold copies or games that are really well made. This should be judged by Scirra, just like they showcase some games on their Facebook and Twitter pages now.
Yeah I know that but I mean it works quite well as an alternative to the default showcase.
That page is too hidden. Most of the users won't find it on their first visit. First impressions are important, there should be a link to that somewhere on the front page.