Nice for first
I know how frustrating it can be making a first game so here are some tips.
Always have music and sound. You can upload music like a regular file in flash, then add it to your library which you then drag it from the library and on to the time line. Sound comes the same way, add it in your movie clips.
Always make a goal, regular jumping around gets boring very fast . Make a small story of have you guy looking for something. It could be a a funny story, the people just want a story of some sort.
Make tokens(coins), they make the player aim for something and keeps them interested. And if you know how to make a shop, go for it, it adds another goal for the player. And goals are good(don't put too many goals or the player may get frustrated).
Make two attacks, the first one can move faster but do less damage, the second one can go longer, and if you know how to make a range weapon, get that guy a bow which is controlled by d or s. I like how you put 2 frames in for the attack.
Anyway, its a good game, and I want to see the full thing come out.
Good luck