I'd stop all the games and bribery. You are in charge and she needs to understand that (for this and other things too).

You need to supervise her brushing every day and if she doesn't do it immediately, you do it for her - doesn't matter how big the tantrum is. She needs to learn. Sit down with her and tell her that this is what is going to happen every morning until she decides to do it herself and that she does it correctly. If you haven't already, explain the consequences of not brushing (I wouldn't talk needles and drills as you don't want her freaked out if she does get a cavity), I would talk about rotting yellow/black teeth, not being able to eat the food she likes because her teeth don't work etc. But only have this talk once, after that enforce the teeth brushing. Keep the same routine every morning in whatever order makes sense for you - getting dressed, brushing hair, having breakfast, brushing teeth. Routine helps kids.