I was working on a serious run for Mega Man 2 after doing a test run. In the test run I beat Clash Man first, and then Metal Man, Wood Man, and Air Man and did part of Top Man's level. In my serious run I beat Clash Man's level. A couple of great time savers were mentioned by Bag of Magic Food. One was about the slide using up the time of the hurt animation. And an even bigger time saver like beating Air Man or Metal Man first. I wish I would've watched Bags movie first before starting my serious run. Before I watched Bags movie, I wasn't sure whether beating Air Man first would save a significant amount of time. Watching Bag's movie inspired me to test to see whether or not you save any time by doing Air Man's level first. I compared how many more frames it took him to beat Air Man then it took me in my test run where I used Wood Man's power. It took him 477 more frames. I then decided to add on to Bag's movie where he ended in Clash Man's level and compare it to my serious run. Originally I was going to do the whole level in Bag's run until I got to a point where the frames lost in the Air Man battle were already made up and more. See for yourselves.
http://dehacked.2y.net/microstorage.php/info/1505/Clash_Man.vbm
http://dehacked.2y.net/microstorage.php/info/1503/Addition_to_Clash_Mans_level_in_Bags_Air_Man_movie.vbm
I'm confident that it would even be faster to start with Metal Man first because you could save at least 477 frames in Air Man's level using the leaf shield. And I didn't beat Metal Man nearly as fast in my test run using the crash bomber as I did Air Man. So I'm going to do my run over again and start with Metal Man.