Below is a list of Xplorer cheat codes that I've made for various games. They may work on other cheat cartridges (Action Replay, Game Shark, etc), but no guarantees! I always put my initials at the end of each game title so I can easily spot which ones are mine. Note that all of these cheats were created for the PAL (UK) versions of the games.
"Gunfighter: Legend of Jesse [MKM]"
Infinite Time
$8007D7E0 003B
$8007D7E4 003B
Infinite Continues
$3007D7F4 0005
Health - Level 1
$300E5F14 0005
Health - Level 2
$300B84C4 0005
Health - Level 3
$30117FA4 0005
Health - Level 4
$300EE8B4 0005
Health - Level 5
$300B228C 0005
//========
"Hot Shots Golf [MKM]"
Strokes To 1 (L1+L2+R1+R2)
D0103864 000F
B0120002 0000
10101C98 0100
//========
"Mighty Hits Special [MKM]"
Infinite Lives
$300F0600 0003
//========
"Monopoly [MKM]"
Infinite Cash
$800DA60C 4240
$800DA60E 000F
//========
"Pac-Man World [MKM]"
Infinite Health
$3015421C 0009
$30154210 0003
//========
"Planet of the Apes [MKM]"
Infinite health
$801E5FF4 0100
//========
"Pong [MKM]"
Opponent 1 point max
$801F2CFC 0001
//========
"Power Diggerz [MKM]"
Infinite Time
$300F734C 0022
//========
"Pro Pinball - The Web [MKM]"
Infinite Credits
$3005E7D8 0009
Infinite Balls
$30063DD4 0001
Infinite Time for Missions
$3005EF04 0032
//========
"Reboot [MKM]"
Infinite time - Family First
$8011339C 1518
Invincible - Family First
$3011314C 0001
Infinite time - Ready the Tr
$8011250C 1518
Invincible - Ready the Troop
$301122BC 0001
Infinite time - Mad Megabyte
$80113470 1518
Invincible - Mad Megabyte
$30113220 0001
Infinite time - Bob Is Our
$80114E54 1518
Invincible - Bob Is Our Only
$80108BE6 0288
Infinite time - Release the
$80112500 1518
Invincible - Release the
$301122B0 0001
Infinite time - Hell Hath No
$80119874 1518
Invincible - Hell Hath No Fu
$30119628 0001
Invincible - Final Level
$800FB502 0288
//========
"Space Invaders [MKM]"
Shields
$300EF47C 0001
Five Shots
$300EF470 0005
//========
"Time Crisis:Proj Titan [MKM]"
Infinite Ammo
$D001E514 6760
$8001E514 0000
Infinite Lives
$D001E83C 6768
$8001E83C 0000
Countdown Stopped
$D0022BD8 66F4
$80022BD8 0000