A good start
I really didn't experience the problems everyone else did. As for basics, it was decent. Nothing really flashy for now can give a little more insight on how things are progressing. As mentioned, a power up system would be nice, as well as more obsticles, but you pretty much nailed some of the key elements missing in your description of things to (hopefully) come.
Just a random suggestion for a stage. Maybe one like old school games where the screen auto scrolls from left to right and you have to jump to different platforms while defeating enemies that are on them to add more challenge. Maybe even a story because most games have a story to know what your goal is (can change midway through as well). Nothing too much needed in the story, just a little insight like the character background or something.
Rating lower now for the so far project, guaranteed higher rating when the flash is finished. Good luck, and thanks for showing intrest in my music!