Thanks for trying our game! We're really sorry that first part was so hard. Truth be told, we had only one week to make the game, no proper playtesting and we only realized people would not guess what to do until the last few hours! We tried implementing some last minute details (like the ? symbol at the door) to help but it wasn't enough.
You ALMOST had it though, trying to use the items on the exit door. Although you were supposed to do that on the other door. Use them on the knob!
If you're willing to try it again, there's your answer. The next room is much easier, a few minutes in and you'll finish the game. ;)