15 Essential Half-Life 2 Mods You MUST Play
4. Research And Development
And now for something completely different: Research And Development. This mod removes all offensive weaponry, leaving you with the Gravity Gun (mostly) to manipulate the environment and solve some increasingly devious puzzles.
It's still set firmly in that familiar Half-Life 2 environment, but Research and Development's gameplay is a refreshing change of playing style and more akin to the puzzle sections of the original or games like Portal and classic adventure titles such as Myst.
The Gravity Gun is a perfect tool to manipulate the environment, solve puzzles and cause all manner of mayhem and the stunning Source physics engine lets this all play out in a satisfying and realistic manner.
Research and Development, like all good puzzle games, is fiendishly difficult, frustrating yet rewarding, devilishly inventive and bursting with personality. If you like puzzles, you must try it.