I take back what I said earlier...about not being able to shoot while you're running. When I first played it, I was playing with the WiiMote, and the default controls had it set so the same button controlled fire and position hold. I played it with the classic controller earlier, and realized the default controls needed to be changed.
Anyway, it's a pretty good game...but I feel a little bit more could have been done to make it better. It should have had more then only 4 weapons (standard, spread, homing, and laser), it should have more stages then just 5, and it should have had the bombs from Contra III.