I too am completely flabberghasted (not a word I use very often) at how surprisingly original and well polished Natural Selection is, especially for a beta 1.0! Amazing work, and fun to play. It's a little bit dry at the moment, but the concept is brilliant, each side is completely different and yet somehow balanced effectively, and in future betas it can only move up from here. And as far as it being a half life shooter... well that all depends on whether or not you like to take control of what's going on. Rush in and shoot or build and organize (building is much easier for the aliens, whereas organization is the greatest ally of the marines). 1.0 is a tad dry, but I'd pay for 1.1 with no questions asked.