Does your metal chain stop if you miss the metals on the ground or if you just miss the “falling” ones?
Do you get more points for the same object if your rank is higher?
The powerups give you more points if collected in surplus: small shot is 100 pts, large shot is 5000pts, option is 500 pts, small weapon bullet is 1000 pts, large weapoin bullet is 10,000pts, one up doesn't do anything since it's impossible to get it in surplus, because there is only a single one in the entire game in Stage 3.
Scoring for medals:
Diagram for showing how you should get them as not to lose your rank/score:
As long as you keep to this strategy, you can miss any, falling or on the ground.