I think it would be the lack of hints, or at least me not getting them, to progress and how often there were interesting things to do. I realise that this was done during a game jam, so i didn't really mark proportional to my reviews, i'm a bit more encouraging with the marks. Also, I jsut realised there's this fun shooter, where you can turn 2D. I can't find it anymore, it's in the asian market.