Research and Development is a puzzle-centric mod for Half-Life 2: Episode Two featuring an unarmed player but plenty of violent mayhem.
I've almost finished playing, so might as well review.
I loved this mod, it was very clever. Some things were a bit frustrating, but then, I'd just do something else, come back to the mod later and solve it. My only real issue is the fact I've spotted quite a few bugs in a single playthrough. (For instance, there's a point where I saw a Combine soldier just standing in mid-air as if he had used noclip, and later on I had the weirdest bug with the buggy.(pun not intended))
All in all, great mod, but there's a few bugs I've seen, one of which is game-breaking and thus needs fixing in my opinion.