The player controls Harry Tasker, who is tasked with the duty of foiling the terrorist plot of Salim Abu Aziz. Each stage has a particular series of goals that the player must fulfill before reaching the stage's goal. Harry's abilities includes the ability to keep his aim steady at one direction while shooting and a diving shoulder roll move that allows him to avoid enemy fire. The player has a health gauge and a limited amount of lives, with power-ups available that restores health. In addition to enemies, there also civilians that the player must not harm during shoot-outs. If the player kills three civilians, he will lose a life and will be forced to restart the current stage.
The portable versions of True Lies for the Game Boy and Game Gear are a bit simplified compared to the console versions for the Super NES and Sega Genesis. The Game Boy and Game Gear version are almost identical to each other, aside for the addition of colored graphics and the omission of a pause function in the Game Gear version. Although the play mechanics are similar, Harry's shoulder diving roll was removed due to limited controls, although all the weapons, except the flamethrower, are included. Only five stages (the chateau, the mall, the park, the docks, and the office building) are included and the level designs are completely different.
Source: Wikipedia, "True Lies (video game)", available under the CC-BY-SA License.