I think what he means is, say, a survival-type mode or "you have five minutes, kill everything you see" or something that's more action-oriented than exploration. A focused, linear shooter game as opposed to what it is. A Contra game instead of a Metroid game.
Which...is feasible. You can say that we can make something like that with the editor, but...can you imagine playing Castlevania 3 like you would Symphony of the Night? Or, again, Contra with a Metroid control scheme? The game styles are the same, but unless the editor is REALLY deep (so far as changing paths, command responses and attack patterns), it's not possible or at least not as easy as some folks think.
That said...I personally don't think it's necessary. MAYBE, like, say, a Boss Rush mode, but that's about it.