Ok now I see what you are talking about with the enemy sets. I did sacrifice some authenticity to make the 2nd half of the game interesting. (Enemy sets, puzzles, new upgraded items)

Level 5 room east of like likes:
Spoiler: show
Push the block to the right to match the other side


You should be able to get the Longbow first without getting key locked. I'll look more into this to see if there are routes that make it possible. To get to the room you are missing, bomb the right wall of the feed the goriya room. If you are finished with the level you don't need to go back for this it's a hint about the boss of the level.