Hmm...
To put it bluntly, it is really crude, even for a preview.
However, I do have some hearty suggestions for you, should you choose to expand this into a finished level.
Firstly, allow me to point out some glaring problems with the level. You will definitely want to deal with these points before declaring your level done, in descending order of importance:
-It is absurdly short and void of any sort of story. Knytts don't have anything to say, and you are not given any information about where you are or what you are doing.
-Two different ways to win, one much easier than the other, but both having the same effect.
-A wall made of blue vanishing blocks that leads absolutely nowhere.
-I can walk into the wall at x=1002, y=1001, which leads to a wallswim, which I can use to get back up to the start and jump into multiple void screens.
-There is a lack of sound for the water. Typically you want to use ambient sounds 13-19 for water FX of various types.Now, I am going to assume that this level is very early in development. For that reason, I really think you should have waited to release a playable beta until your level was at least halfway finished.
Secondly, you should definitely take a look at other peoples' levels, particularly ones that closely relate to the type of level you want to build. Play them, open them up in the editor, and learn how they work. Then decide what you want to try and replicate in your own level.
Thirdly, you need to ask yourself: 'What can I do to make my level special?' There are numerous ways you can do this. You could utilize one or more of the following:
-Use imported music in your level, (with the artist's permission) as opposed to the standard KS soundtrack.
-Use a custom tileset or two to give the level a truly unique look.
-Think of inventive ways to use the objects given to you in the editor to make interesting and/or challenging puzzles and obstacles. Toy around with objects and learn how they work.
-Tell a fascinating story. This is often the most difficult part, but a great story will carry a level farther than you might think! Of course, you don't NEED one, but it is an option.
-Create and use custom objects, if needed.Remember, anyone can make a level for Knytt Stories in about 2 minutes, but the truly good levels may require months of work! Decide how devoted you are to this craft, and here's hoping you make something special out of this.