Due to sdkess's brilliant minimalist run, I decided to continue to hack away at this game and try and redeem myself by doing an all levels run. My main conviction for doing this is that this kind of run seems to be very popular (to watch), and extremely annoying and frustrating (to actually do, which is not really the convicting part).
The main difference I noticed between Super Mario Bros. 2 and any other 2D Mario game (besides the fact that it's not technically a "Mario" game, in that it wasn't designed with Mario in mind) is that there's very little room for error. In SMB, SMB3 or SMW, if you get hit, it's not really that difficult or time consuming to get a mushroom to improve your room for error. In SMB2, getting a mushroom is time consuming, and you also have to know every inch of sub space to do so. Or you can meticulously keep track of how many enemies you've killed so you can get a heart. So, needless to say, getting hit even once in this game makes for a very nerve-wracking adventure through Mario's dream world. All this was pointed out to justify my idiotic death in the very last level of the game. It's not pretty, but let's be honest: neither are you.
For reference, there are only two places I planned on getting hit: in 1-1 and in 2-3. The rest are either accidental, or I didn't care. This is actually a very good run, up until 7-2. I calculate my actual personal limit would by around 25:30, so I made about a minute of mistakes. 1-1 is particularly sexy, if I do say so myself, and it took me roughly a billion tries to get it down, as there's only about a two-tenth second grace period of error. If you're more than two-tenths of a second late, you miss Birdo's egg, and you'll have to wait three seconds for him/her to spit another one at you.
Sorry about the hideous quality; my VCR and I have already had a conversation concerning this. Enjoy!