Alright I took an image I did a few weeks ago and made a little animation of it.
Flash CS3
399 frames
5 delays
Tiles are 1 color + Black and do not touch edges of each tile
All character animations are nested into the town.
Backdrop scrolls and carries all of them.
This is cool because you can work each characters animation and see all of them animate together when you go up a timeline.
The loop is created by having another instance of the town to the right of the main town, that way it replaces the orginal position at the end.
1 frame is dropped so that the first and last frame are not the same, thus its a 400 frame animation -1 = 399.
Main dude doesn't actually move, except up and down, he just runs and place as the nested object scrolls behind him.
Measured out all the tweens so that there is no jittering.
Used 8x8 grid for almost all movements except some of the y-axis stuff and birds.
Didnt do parallaxing but gonna add that in.
I think that flash works well for this sort of thing.
Looping and choosing animations is easy, nesting is usually straight forward to implement and navigate.
All in all went fairly smooth and was fun to make.
I'm gonna try to do some more of these with different ideas.
Apparently my basic math skills are terrible.
There was in jitter in the scrolling as he walks down the first hill just before the lamp post.
I fixed it by setting the town to finish scrolling at frame 401 and the main timeline at 400.
Then checked each frame in graphics gale to make sure each frame scrolls 2 pixels.
Here's the fixed version.