How in the world do you beat Hun in challenge mode?
 

Once he goes red, he wipes the floor with me.

If it matters I'm playing on the PC.

he is easey, but it if it is PC then I cannot halp you there.

I've beaten him on PC, He's easy. Just run and run and run. Hit him when he's not attacking or when he's on the back.

I'm having some problems with Baxter though :cry:

pick Mikey and be CHEAP. Use the Shell Sweep on every character you can. I beat challange mode using Mikey by doing that to everyone, and saving up all my ninja stars for people who are too hard to be cheap to. (Shredder/Oroku Saki/Yoshi/Hun)

For Baxter, its easy when your Mikey cuz you have that "Helicopter Kick" that you can repetitively do to his face. Watch his power meter fall! :D

I hit him and ran away until I got low on life, then i threw shurikens at him.

The dash button is your friend.When Hun turns red just dash around making sure to stay out of his reach.If you master the dash,you can usually either manuever mehind him and hit him in the back or blindside him and smack him around.Remember though,just smack him two or three times then run like hell.If you try to go toe to toe with him,he'll usually get the better of you.

speaking of beating hard guys, i cant beat krang in ninja turtles 2 the arcade game for nes. can anyone help

My memory's a little fuzzy on that.If I remember correctly you have to jumpkick him a couple times then jump away before Krang counterattacks,rinse,repeat.
Also there is a code that'll get you extra lives and I think there's also a stage select as well.

awesome it worked needed those extra lives

i just throw the fire shurikens at hun till he's dead :P