heres some tips...
When u have 30 or 40 odd bullets to spray in a straight line... speed as fast as u can... then let go of the up key and turn 90 degrees or there abouts... then fire them all quickly... you will go to fast for it to recognise collisions.
for missile shots... hold the down key and fire till you are moderately fast... then let go... the missiles should just curve around you constantly and not hit you
for shotgun shots... speed up till it wont go any faster (Normally about 2 times going over the edge of the screen holding up) and then fire all your shells. let go of up... turn 90 degrees (as close to as possible) and tap up until your out of the range of the middle bullets (You'll know what I mean when you see them).
The speed techniques won't work with 4 way shotguns
and grenades you just have to grin and bare (and you wont be grinning on the 8 way one)
That should get you to the end of the game.
for level 58... there are two ways that are pretty easy depends which ur better at... the first one is to shoot BFGs from corner to corner of the map and hide under it (May take practice to move diagonally underneath it).
Or I find the easier way is just an all out offense.
Lightning - Short Shield - Energy Missile
Just hold em down... or lean the pattern as everything can be dodged easily apart from the v.fast planes... so learn which order they spawn and shield up ready for em... u should lose about 1/4 to 1/2 of ur health and it should be over quickly.
the 5 day scores are clearly cheats... its impossible to do without... that involves completing every accomplishment on every track each day... clearly they have a speed hack or something and 5 days is the minimum they can finish in.
 "Smatch"){kind=icon}
 "I Am An Insane Rogue AI"){kind=icon}
 "Burrito Bison"){kind=icon}
 "A Knight's Story 2"){kind=icon}
 "Dead Drunk 1.3"){kind=icon}
 "Frontier"){kind=icon}
 "Diner City"){kind=icon}
 "Test Pilot"){kind=icon}
 "Bullets"){kind=icon}
 "Heavy Weapons"){kind=icon}
 "Learn to Fly"){kind=icon}
 "Zening"){kind=icon}