I have to comment one more time.
You need to really push yourself if you want to make an interesting level. How dedicated are you to making a great level? You'll have to decide how much time, energy, and determination you have for your project.
Right now your level (what little I've seen) does have a kind of claustrophobic, maze like feel. Is that what you want? If so, go with it, make it more maze like, more confusing. Were you wanting it a little more open? What kind of environment do you picture Juni going through here? Is this an ancient Greek labyrinth, an Egyptian one, alien, sci fi, a cave, or what? There is a tileset you can use for each of these if you look through the public tilesets. Maybe you'll want each of these styles for each different section. Does the shift from one area to the other seem natural or forced?
You are also basically going to be an decorator, so you have to have an eye that can recognize what looks good and what is simply boring. You can learn to do this simply by being critical of any and every game or image you look at. Feel the game. Your ability to be visually critical, like any part of your brain, is a muscle you develop with practice.
To develop your level, try copying and pasting a screen you like 2 or 3 times and work each one up a little differently. Play with the tilesets, see what you like. Play other levels and see what about them is exciting and interesting and learn from that.
Ok, I've played art teacher long enough. Hope that helped.