Cannot Progress in DMC 1 due to BOSSES NOT SPAWNING!

[pasagoa]

I'd first like to say how the lion shadow in mission 4 did not spawn, instead the game gave me a couple of grim reaper enemies to deal with. However I didn't think anything of it at first and progressed on. It was then on mission 7 after I defeated the goat man and got the life draining key that I noticed the Spider Phantom did not spawn in for a third time, instead the area had lots of puppet enemies instead. The door was still locked (it had the massive hand) when I tried to leave and there were no more enemies to kill.

I searched all over the web an couldn't find anything so if anyone could help it would be much appreciated as I just bought the game and was really enjoying it up until that part!

[Electric Cupcake]

Are you on Easy mode? You don't have to fight the Shadows or run from Phantom if you accept easy mode. To escape the sewers, you just have to defeat all the regular enemies to open the door. Just look around and search for any you missed.