Based on the second book in Riordan's series, Sea of Monsters chronicles a story in which Percy must save «Camp Half - Blood,» the safe haven where demigod kids are protected from evil by magic barriers. (screenrant.com)
If it's a coloured magic barrier that's halting your progress, then it's a case of finding the corresponding floating brain and bringing it to an end. (gamespew.com)
It's also a nostalgia - fueled trip back to the days of video game design where color code magic barriers that could only be removed by killing the matching colored bad guy were a thing. (wolfsgamingblog.com)