Manual aim warning:-  While the manual aim mode does make the game challenging, it can prove difficult when you can not hit a distant target. It will take awhile before you can hit distant targets accurately, so practice on enemies that are not too far away. When you can hit them accurately, attack targets that are a little farther away. Eventually, you will be able to hit almost anything at any range. Just remember that the higher the cannon is raised, the higher the shell's arc becomes, and the shell's distance increases. If you get good enough, you can eventually hit a moving target with the Cobra's special weapon, a guided shell.

Kill two helicopters with one shot:-  If two helicopters are close together, you can usually kill both of them with one shell. The shockwave from the shell will destroy the both helicopters.

Game Shark Codes 

Joker Command D008E6AC ???? 
Infinite Shield 800B7564 00C8  800B7566 00C8  800B7568 00C8  800B756A 00C8 
Infinite Cannon 800B7708 0008 
Infinite Guided Missiles 800B76AE 0008 
Infinite Ion Cannon 800B7678 0100 
Infinite Specials 800B76D2 00E8 
Infinite Mines 800B76F6 0010 
Infinite Phoenix Missiles 800B76C0 0008 
Infinite Plasma 800B768A 0100 
Infinite Laser I 800B7654 0100 
Infinite Laser II 800B7666 0100 

Secret Tank Codes 
Venom 800B6EA8 0003  8010C390 0003 
Viper 800B6EA8 0004  8010C390 0004 
Cobra 800B6EA8 0005  8010C390 0005 
Rattler 800B6EA8 0006  8010C390 0006 
Fang 800B6EA8 0007  8010C390 0007 
Death Adder 800B6EA8 0008  8010C390 0008 
Python 800B6EA8 0009  8010C390 0009 
Desert King 800B6EA8 000A  8010C390 000A 
Anaconda 800B6EA8 000B  8010C390 000B