Hey, I was just wondering if anyone had half life 2 on their computer and wanted to download the mod 'Synergy' for a future games session. Basically, it turns half life 2 + episodes into a co-op game, which can be hilarious fun. It's on steam under the mods section if anyone's interested.
There are also some crazy hard game modes, which can also be really fun - one called Trials, where you basically have to complete a series of trials, some puzzle based, some skill based. There are also puzzle maps, which includes one of my favourite puzzles - you have to get to the top of a mountain, except there are no stairs, only magnetic cranes and giant metal crates. You do the math.