Most game systems just say critical hit, is the thing. From D&D to Final Fantasy, the term is a Crit, not a swell hit. Calling something "Swell" just sounds like 50s slang or something, and it's kinda weird.

Best homebrew game system I came up with actually used a deck of cards in place of dice, and had only four stats. Was actually pretty cool, the playtesters loved it!