Up until recently Half-Life 2 Episode 2 was going to be available separately, but now that has been canceled.
Instead, in order to get Episode 2 you'll have to buy it with Half-Life 2 and Episode 1 even if you already have those games...
Their excuse is that you can then give away the unregistered games you already have....
Games are over-priced as it is IMHO, now they want us to buy the same game several times? Ridiculous!
Guess I won't be buying or playing Episode 2...


