Research and Development is a puzzle-centric mod for Half-Life 2: Episode Two featuring an unarmed player but plenty of violent mayhem.
Absolutely fantastic, manages to bring fresh and new gameplay to half life 2 whilst making it still feel very much like a Half Life game!
I hope Valve look to this mod for inspiration when making puzzles for episode 3, rather than just reusing that see-saw puzzle they made us do 20 times already :P
The start was amazing, I really really enjoyed it and the cart ride thingo was the most fun I'd got out of Source for a while. However, the boss fights were tedious, the vehicle section was glitchy (I wasted about half an hour thanks to one particular bug) and the Strider fight was just plain frustrating.
A good game from an amazing team that I (mostly) thouroughly enjoyed, it's just a shame the end let it down.