5445. First try. I may have played too many bullet hells.
This is very similar to a game I saw on a TI-83 (the graphing calculator), but the other one used solid bars for the sides instead. I think that one was easier on the eyes, though not by much. Also, while I don't think it was a 3310, I did actually have a Nokia phone back in the day. The blurring some people see as a result of the movement being fast and not interpolated in an expected way happened on the real thing too.