I don't have a whoooole lot to say, but while the gameplay is the same as DOOM, the level design is completely different. Where DOOM was labrynthine, DOOM II is all puzzles. Pretty much every level has an easily identifiable design idea, though loads of them are kinda just jokes? It definitely feels like it takes itself even less seriously than the first. Personally, I found the levels much less frustrating than DOOM at it's worst, though it never quite reaches the highs of DOOM EP1. In general? Good fun.