Use Lunar IPS to patch the either the US or European release.
The Genesis (Mega Drive) requires games to have a correct checksum to work with,
which is why only one patch should be applied to the ROM.

Probotector is a PAL ROM originally only running @50Hz. There is the option to make the game 60Hz.
Infinite continues work if the counter is stuck at 6 remaining continues.
Japanese Hit Points patch is done by MrNemesis for both the US and European version.

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Description of MrNemesis' patch:

This patch restores the ability to take three hits, complete with the life bar.

In addition, this patch does the following:

-Restores the three cheat codes that were also present in the Japanese version 
but removed from the US version.  Note, however, that unlike the Japanese version, 
these codes are entered on controller ONE.

70 lives	At the main menu, press C, B, A, Right, Left, C, B, A, Right,
                Left, C, B, A, Right, Left.
All weapons	Pause game play and press Up(2), Down(2), A, Up(2), Down(2), B,
                Up(2), Down(2), C.
Level select	At the main menu, press A, B, C, Left, Right, A, B, C, Left, 
                Right, A, B, C, Left, Right.

-Up to ten lives can be selected in the menu.  (The default is three.)
-Player 1 and Player 2 can now select the same character.
-A new code is available that takes you to the game's debug level! Press Left, 
Right, Left, Right, A, B, C, B, A, Up Down.