Combine: Pixeljunk Tandem Tag-Team Edition

Second: Pixeljunk Monsters and Pixeljunk Monsters Encore.

I'm not sure what the official site policy on expansions is, but these are downloadable packs that require ownership of the original game and add to said base game.  If there's not a page for more substantial download-only packs like The Lost and Damned, there shouldn't be a page for smaller content for less prolific games such as these.