For the game, spiked and speared are exactly the same. The issue was enemy vs beast. A foreign enemy refers to a human from a different ship/country/whatever. The attackers here are mermaids, and they are definitely not human, so they are not enemies. They are beasts.
I really don't like the fact that they made this version harder than the original with no option to tone it down. The original was already difficult enough as it is, so why alienate all the casual players like myself by making it more difficult? It's not like they made any necessary improvements with the controls either, as they're still just as sensitive and slippery as ever! Other than that though, it's a really good reworking of the game, but those two key factors still ruin it for me. Thank goodness I was one of the lucky ones to get both the GOG release and the original Android port of the Dreamcast version when I still could.