That was my second attempt, the first ended tragically early :)
My HP was near zero when he had about a third left, and at that point I switched to a much more conservative strategy: Keep running, and fire the E-Missile as soon as it charges. That got really grindy but it did work, he didn’t hit me at all during that time.
Difficulty, I’d say is appropriate for a game jam, but in a real game you’d want to go a bit harder.