Alternate Paintjob:

 To  choose  your  alternate  paintjob  in Main  Game, Practice or Boss
 Attack mode, press the R button at the plane select screen.

 To select the alternate color in Death  Match, hold the R button while
 selecting one of the four original planes. 

Bonus Plane:

 At the  "PRESS START"  screen, press C-Left, C-Down, C-Right, C-Up, C-
 Left, C-Right, C-Down. 

Extra Planes in Battle Mode:

 To earn six new jets, beat the first two stages to earn the MIG 25 and
 MIG 31, complete the third and fourth  stages to earn the F-22 and KFR
 C2, and finish the game to earn the EFA and RAFALE. Good luck!