So I got curious and did some searching on any kind of replay/spectator feature in the game. There were some videos on youtube (including the trailer) that showed a replay being played, but I couldn't find anything in game, which is a downer because this game needs something like it. I had a sniff around in program files and to my delight found a folder named "replays", inside is "replay.bin".
We should look into this because I'd like to see some worms montages
Xsplit can record it but its a cunt to set up for Worms