So I tried your level, and to start things off positively, you seem to have some fundementals down. The level is very playable for the most part.
However, i'll some up issues I had while playing this:
-The level seems very based off of Yoshi's Island 1 and 2. It is a little too obvious in my opinion. A little more creativity would suffice, otherwise people might think you just blatantly edited the level itself.
-The first Dragon Coin is above the lower half of the screen. I would suggest either leaving a hint by putting a coin trail below it, or change the vertical scrolling to 'At will' by pressing
in Lunar Magic so that you can freely scroll up.
-When shooting out of the pipe, you get launched into a bunch of Rexes and that can't be avoided. I would suggest moving or removing the one behind the one in front.
-Lastly, if you haven't enabled the Switch Palace yet, the jump before the clouds and the 1-Up Mushroom (again, should be a little more thoughtful) becomes very tedious because a Banzai Bill comes right after that, making you have to jump back to the previous platform or get hit in a forced way, and that's not a good thing.
You also seem to have forgotten the goal point, but that's not a big deal as long as you fix that.
For a first hack, i've seen worse, but at least fix the first issue because the level doesn't look like there has been put a lot of effort into. Fixing the other things would also be useful but not AS strict. Hope I helped.