There's not a lot of games that have children running around that you can attack unless it's modded, but today in Tales of Graces f for the PS3 I got to a part of the post game called the Zhonecage.
*** possible spoiler warning if you're planning on playing this 5 year old game ***
The Zhonecage is the EX Dungeon of Tales of Graces that's only available on the "Tales of Graces f" version for the PS3. On the first floor I'm greeted with child versions of the characters as random enemies, so it seems that I'm killing children in the first floor of this dungeon. Though they maybe just holograms or are humanoid androids but there's no context explaining that, so I'm lead to believe that these are real children.