“It’s dangerous to go alone” — Sure, why not have a game in which there are two characters working as a team? You can only control one and the other is a computer-controlled character who obeys “STOP” and “COME TO ME” commands.
“Take THIS!” — On its own, this makes me think about attacking. As in, someone’s about to punch you. I’m leaning more towards environmental hazards that occur if your partner gets too far away from you. Something silly and comical that makes no sense otherwise, maybe — something like a weight falling on your head. Like after a time limit or something.
Trying to combine the two I think of something where you have a partner that follows you closely. Upon reaching certain obstacles, however, there’s a timing element to get past (like pistons that can crush you), and you can’t both go because your partner is JUST slow enough to get crushed when you avoid it. So you have to let him stay in one spot, and then a time limit starts. Gotta get past the trap or else that weight will fall on you and so you’ve lost a life. Once you’ve gotten past, your partner teleports a few behind you (so that traps can be chained, leaving space for pausing between obstacles to get timing right), and you’ve both gotten through safely.
Probably won’t be able to get this done in time on account of other commitments. Damned end of the semester deadlines.