2

Many improvements can be made....
Less is more. Use less enemies, but put them in effective spots.
Never put 2 locked doors on top of each other.
Never place a switch or a mine under gold.
Try to place the gold... more.. creatively. Gold in big groups like that? No no.
If you block something off with any door, try to keep it to ONE door.
Mines that are 1 space apart can stop the ninja. Don't use extra.
Be a little more creative with your tileset. I like it when there can be angled jumps.
Avoid 3 floorguards on one floor. Two will pile up on top of each other when they hit the edge, making one of the three totally ineffective.
Make it less linear, leave more than one obvious path.

Oh, and I read somewhere that you want to keep a balance between filled and empty space, in terms of tiles.

"i want to see if someone can beet it."
No no no. You should be able to beat the level on your own. If you're not that great, you should at least see if you can beat each part. That is not what you should be thinking when you make/submit a level. If anything, your first comment should be a completion demo.

demo...

Demo Data	31:1118481|0|71582796|71582788|1636

Try to see where