Thanks for the comments. Regarding the barrier, that is actually a function of how I had the jet pack working. I didn't want the player to be able to get items that were meant to be collected under the reverse gravity. It was meant to simulate that the jet pack's thrust could only lift so high.
As for the sameness, that was actually intentional in order to try and meet the "multiple runs" theme. Having to try and remember which door was which could force the player into re-entering an area. However, if I do expand this game idea, that is definitely a change I want to make so I appreciate the feedback.