Research and Development is a puzzle-centric mod for Half-Life 2: Episode Two featuring an unarmed player but plenty of violent mayhem.
Updated 17 July 2009, fixed several issues & added a dynamic crosshair when using the keypads & lab buttons. Requires Episode Two.
This is the installer version. Hopefully it should fix an issue with the mod not showing up on steam games list at all.
Very late edit:
This mod was created by mbortolino, send your PM's to him about the mod.
I(DuckSauce) simply created this installer due to issues people had with the regular zip files.
Editted in now because Mod of the Year kicked in, who knows what people will flood here and get confused :P