Research and Development is a mod released for Half-life 2: Episode Two, made by someone named ‘mbortolino’. I really can’t find anything else on the man past that name, which is a real shame because if this isn’t the only product of his work then I really want to see the rest.
RAD is a short two-hour adventure in the HL universe, where you again battle combine and zombies as you travel from point A to point B. The key difference here is that you don’t actually use any guns, with the Gravity Manipulator only showing up after the first 45 minutes or so. Instead you have to pass a series of physical obstacles by putting your mind hard at work, and this is where the mod really shines.
All encounters are fairly cerebral experiences, and each test a different part of your own personal skill. Sometimes quick reactions are required, whilst other times you need to sit and understand the whole concept of what you’re trying to accomplish before setting that plan into action piece by piece. It’s an incredibly varied adventure which, aside from the occasional Source Engine malfunction and a short section with swinging bridges, is both well paced and incredibly thoughtfully designed.
What I found most amazing about it is that really it makes somewhat more sense than the regular HL2 campaign, as you do play a scientist it seems perfectly rational that he has to use his brain more than anything else to get through certain situations. The extra hoops the game has you jump through to get the afformentioned Gravity Gun enhances the feeling that you’ve really earnt the device, and there’s just an awful lot else here too good to spoil. If you can then I really do emplore you to give it a try. Again though sadly it does require you to own ‘Episode Two’ rather than vanilla HL2, but as Steam have a sale on where the episode in question is only a 1/3rd its original price I’d say now is the time to check it out.
(Also; Mr. Whirly is legendary)