Just what the title says: Freespace has a storyline that seems perfect for an anime (especially the first one) with its strange, seeminly unbeatable alien race, the Ross incident, the first Shivan attacks on the Player's convoy, etc and it has ship designs and weapons (beam cannons! Can't get any closer to anime than that!) that seem like they were made for an anime. Not to forget the lock-on mechanism that looks like what you'd expect on TV.
Sorry, just a random brain fart.