The major thing is "hold down the FB to do X"... Not sure, there is a need (yet?) to flip the ship or swap the weapons that way... Ofcourse im comparing this with games like Katakis or X-Out... Maybe, if you want to have multible weapons(ystems), you want to consider F-Keys? And for slipping the ship, the spacekey? "Holding down the FB" is very confusing for this kinda game. This mostly used to "charge the supergun" n stuff ;-).
The rest of the controls seams to be good to me. Ship isnt too slow, controls are direct and the ship moves, as it should.
Collectable items... Maybe a bit less of 'em and maybe mark 'em with letters or diff colours, if they have diff features/funtions. Or go straight down the lane, that collection an container, it'll upgrade the weapon (not using a weaponsytem), everytime you grab an container (that's why you should reduce the containers, or make 'em look diff). Ex. "Blue containers" gives a temp. shield, "Red containers" gives you an weaponupgrade", "Yellow container" gives you an extra life, "Green container" gives you bonus points, ... thank kinda stuff.
At the end of the day, it's your game, dude :-). Feel, whatever you want to do! You're on the right path and i'm just a dude on the internet :-P.
/cheer