Ended up playing losoall's instead since someone already hit Jorshamo's (sorry!).
Your design is a little questionable, especially for level 2 of all things. The way you use the girders is fine in general, and I rather like the Bob-Omb block gimmick, but the level itself lacks a real progression. As far as I can tell, the first instance of said blocks is at the SMWC coin (in which you need to drag a springboard from later back a ways, which I'm not sure I agree with either). It IS a good idea, but it needs to be introduced and executed better, especially if you're going to do it this early in the game.
Here are some screenshots.
Don't really see the point of it/like it. It'll either act as a blind trap if you try and go up, or the Bob-Ombs will simply walk off the edge.
The block's palette is red. I'm assuming this is simply because you altered Mario's palette to work with the blocks (I've actually changed their palette in the latest base ROM if I recall, so it might be worth check it out).
This part is tight + a little too hard for level 2.
This is the first instance of these blocks. No sort of introduction or obvious way to break them is given. I found out accidentally at a later time.
You could have added text to these so we can test, you know (and in fact, I'd recommend doing so once you update your level again).
I'm beginning to think we should insert a Bob-Omb generator into the ROM (or you should put reset pipes in each of these areas). In this particular case, even putting a 16x16 block at the end of that platform to block the Bob-Omb from falling would work.
Too hard to dodge these. I'd just extend each platform.
Kind of hard to blow these up.
Overall thoughts:
-There is some quality design here, but the level is lacking a real sense of progression.
-Tight spaces here and there which are a little inappropriate for the second level.
-Introduce the Bob-Omb block gimmick in a more reasonable way.
That's all.