The reason it felt frustrating to me is because there isn't much room for improving your time to clean the room besides trying to press the buttons faster or choosing which items to pick up first. Preivious levels felt like no challenge then I get to level 3 and every time I come close but no cigar.
Thanks and sorry if I sounded harsh. I didn't get to mention that the concept of cleaning up a dungeon after a player slaughtered your goblin friends is a funny way to spin it. I hope you take it and run with it. This could make a very great puzzle game.