Swan Song makes the game a bit too easy, between it and mechanoreception you can have a constant stream of birds floating in, even when under a plane. maybe put a cooldown on it so that you don't end up with a constant stream of swans? The black swan could ignore this cooldown, so that it's still a rare and powerful part of the flock.
Great game, it's a lot of fun. I'd love to see some Champions Leagues though, and maybe some sort of benefit to staying with a team, rather than transferring whenever possible.
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