- [PROTOTYPE] has a minor one at the very end: over the credits, audio from a news report plays, which starts off with a random citizen talking about how the Marines risked their lives to save New York City and how everyone's extremely grateful to them. What makes it heartwarming is that Blackwatch, the secret military division that deals with biological weapons (and is composed of nutcases that have no problem with killing healthy, innocent people For the Evulz) was planning on nuking the city to prevent The Virus from spreading and having the Marines take the fall for it.
- Attached to this is the simple fact that despite the overwhelming carnage of the virus, New York City has weathered the storm and is showing signs of recovering. And it's in large part thanks to a certain sapient biological weapon that's developed a conscience.
- Dana's eventual acceptance of Alex because they're family. Of course it was cut short....Alex: Dana, I'm sorry. I didn't know what to tell you. I need to know why. They made me this way and I need to understand.Dana: It's alright, Alex. It's fine. Look, no matter what, You're still my brother.
- You can also Pet the Dog if you so wish when you come across an infected or a rather sadistic Blackwatch soldier menacing civilians, you can step in, save them, and toss their aggressor a mile or so down the street. Of course, this requires an almost surgical level of precision without killing the people you're trying to save by accident.
Heartwarming / [PROTOTYPE]