* The fact that, even after twenty years, humanity is still fighting against the odds.
* Alyx greets Gordon with a huge hug at the start of ''Episode One.''
** Let's be honest--virtually every single interaction with Alyx is an exercise in Heartwarming. She's just that nice.
* At the very end of the Ravenholm Mines, there is a minecart trap that includes a spinning blade, which you use to kill the remaining zombies before escape. If we think about this, Father Grigori managed to swim through the Ravenholm mines, climb over fences that Gordon ''can't'', and fight the infinite horde of headcrabs, all twice just to help any rebels that come by and to tend to his flock. He could have left, seeing how close he was, but he didn't. Also counts as Awesome.
* The original credits theme for ''VideoGame/HalfLife'' popping up in ''Half-Life 2's'' credits can be pretty heartwarming for someone who finished both games.
* In a meta sense, how thoughtful was it for the former lead writer of Valve, Marc Laidlaw, to provide some form of closure for the ''Half-Life'' franchise when it became quite clear that the company wasn't going to continue forward with the series? After ten years since the release of ''Episode 2'' back in 2007, Laidlaw provided the fans who've waited all this time a blog post in August 2017 of how the story would have ended had ''Episode 3'' actually been released.
** Doubles as a potential CrowningMomentOfAwesome seeing as, with the hoard of unused assets and concept art from years past and finally a synopsis for Episode 3 sparking renewed interest, and all in the wake of a near fully-formed FanRemake [[VideoGame/BlackMesa of the original game]], fans have everything they need to potentially do what Valve won't and make Episode 3 themselves.