Isn't the structure too difficult? Too many stages?

Just to complete two rooms here, you'd have to focus on this game all day to even finish one room, and I've had to continue multiple times without using any items... How do you all manage... It might be purely fun and rewarding as a puzzle, but with the hidden quests having rooms 5 onwards all with the same deadline, how much do they want you to give up... Completing even room 2 casually is a bit tough, so room 5 is probably impossible unless you're someone who can really get into it and manage your time well. I'm almost at the dungeon clear though lol