The arrangement is much different, and while the Sonic Adventure version consists more of acoustic and live-recorded instruments, the Sonic Adventure 2 version consists more of electronic sounds and much more programming. There are differences between the Sonic Adventure version and the Sonic Adventure 2 version.

He talks about how he never wanted to be given the lonely job of watching the Master Emerald with lines like, 'Is this the way, the path I chose?' However, he still fulfills his responsibilities as Guardian like when he says, 'My duty is to save the flower from evil deterioration.' He also talks about his great strength and stubborn personality with lines like, 'No-one stops Knuckles' feat,' and 'Cold and stubborn but I'm still gon' live it.' Knuckles even mentions his rivalry with Sonic in the line, 'Don't approve of him, but gotta trust him.'

Like most of the character theme songs from the Adventure games, the lyrics of both versions of 'Unknown From M.E.' are written in a way so that Knuckles himself is talking.

Here i come tougher than knuckles