Pause the game and type "RUSSIAN AIR", then unpause the game. Press 'N' to skip levels. This doesn't work on all versions.
ITEM ---------- COST - COMMENTS
Advice --------- 200 Only useful after Level 1
Speedup -------- 500 Essential to survival
Half Health ---- 500 Restores half your energy
Autofire ------- 500 Needed if joystick has none
Nashwan -------- 600 10 Seconds of sheer heaven
Full Health --- 1000 Restores full energy
Rear Shot ----- 1000 Very effective on later levels
Small Mine ---- 1000 Useless
Side Shot ----- 1000 Cannot be used with Rear Shot
Electroball --- 1200 Too sensitive to control
Power-Up ------ 2000 Double bullet size
Large Mine ---- 3000 Useless
Double Shot --- 3000 Recommended on later levels
Cannon -------- 4000 Effective when using two
Dive ---------- 4000 Waste of Money, but fun
Missiles ------ 4000 Weak to start with
Laser --------- 4000 Awesome when using two or more
Drone --------- 4500 Two slow
Flamer -------- 5000 Extremely limited range
Bomb ---------- 5500 Limited range but powerful
Extra Life ---- 6000 You'll need lots of these!
Homers -------- 6000 Four slow but powerful missiles
Protection ---- 6000 Doesn't do much
Bitmap Shades - 6000 Darkens Screen - useless
Try to stick with your best weapon, and end up with 2 Cannons, 2 Lasers, and either Side Shot or Rear Shot. Always spend your money as you cannot take leftover cash.
LEVEL - SHOP - ACTION
-- 1 --- 1 - Buy Health and Super Nashwan
-- 1 --- 2 - Sell Rear Shot, Buy Double Shot and Side Shot
-- 2 --- 1 - Buy Side Shot
-- 2 --- 2 - Sell Side Shot
-- 3 --- 1 - Buy Health and Rear Shot
-- 3 --- 2 - Sell Rear Shot, Buy Side Shot, Laser, and Power Up
-- 4 --- 1 - Sell Rear Shot and Side Shot