I don't know why he chose Minesweeper specifically, but he wanted something less original (less so than a scarf), so that people would criticize the game, rather than consider it "original" and increase its rating just for fun.)
Added 4 minutes later
Siv, by "killing in a special way," I meant the Thieves' Guild quest (or a couple of them), and the rest (of which there are many) don't involve killing at all.
Yeah, I agree, the game is almost entirely linear, but even with that, it's pretty good! The story is decent, and there are some interesting quests (maybe not all of them), and the world itself, with its atmosphere and structure, is enjoyable!