The Famicom Contra is an interesting beast. Although the basic gameplay is the same, there's lot of little graphical effects found here that are absent in both the overseas versions - the trees of the jungles blow in the breeze, there's sporadic snow in the arctic area, and the floor of the final level eerily pulsates. What's more is that there's an actual intro this time, as well as a map screen (a la Castlevania) and minor debriefings after each level. The story had been altered a bit too - in America, the Contra games were meant to take place in the present day (the 1980s, back then), but here take place in the year 2631. There's a slightly altered ending, a hidden message from Red Falcon, and a sound test. Some will claim that its harder, though I've noticed no difference.

The European Probotector was based off the American version, so it too lacks the bonuses of the Japanese cartridge. However, all of the characters have been changed into robots. Even the little medal life indicators have been changed to little mechanical figurines. The rest of the game remains the same. Check this for comparsions: