['Design Lesson 101' is a regular column by Raven game designer Manveer Heir. The challenge is to play a game from start to completion - and learn something about game design in the process. This week we take a look at Konami's PS2 port of the original Metal Gear.] Being once a PC gaming zealot, I missed a number of console games during my youth. After the Sega Genesis, I didn't own another console until a few years after the original Xbox was launched. As a result, there have been a number of big franchises and games I've missed out on, and I've been slowly trying to catch up on them. One such franchise is Konami's Metal Gear series. With Metal Gear Solid 4: Guns of the Patriots having been recently released for the PS3, I decided it was high time I checked out the Metal Gear series, starting at the beginning. The real beginning, though, with the original Metal Gear for the MSX (or at least the ported version of it, which is available on Metal Gear Solid 3: Subsistence as an extra). In playing the game, I was reminded how difficult and obtuse at times older games can be. What I found most interesting, however, was how the difficulty changed over time. Design Lesson: By employing an inverse difficulty curve, Metal Gear is able to change the style of its gameplay as the player progresses. Modern games do a fairly good job of introducing the player to new mechanics slowly. To help them along, designers often make sure the beginning of the game is the easiest, and difficulty increases incrementally from there. Metal Gear's difficulty is flipped. While the player is introduced to new mechanics slowly, the beginning of the game is the hardest part. Solid Snake is given no weapons or items and charged with infiltrating an enemy base. This means punching is the only method of attack available at the beginning of the game. Stealth is of the utmost importance during the early portions of the game, as a result. Sneaking around patrols to access new areas is how the majority of the beginning of the game plays. Being spotted alerts the guards, often leading to death or at least significant injury. Rations to restore health are rare at this stage in the game. Soon, the player comes across a pistol, rations, and some key cards that open up new areas of the game. Part of Metal Gear revolves around saving prisoners. Save enough, and Solid Snake gains in rank, which ups his ammo capacities, maximum life, and number of rations that can be carried. This is seemingly the primary game loop of Metal Gear. Sneak around, find objects that will gain you access to the next area, save people along the way, and rise in power over time. By the time the player gets new weapons later in the game, like the grenade launcher and missile launcher, he is rather powerful. The enemies increase in number and strength, but not enough to counteract the strength of the player. At this point, the gameplay changed for me. No longer was I supremely worried about sneaking. Sneaking was still a way of progressing, but I often found myself just running around the rooms trying to figure out where to go next. If enemies spotted me, I dispatched them easy. Instead of dealing with enemies being the primary obstacle to game progression, the finding of the correct items to progress to the next area became the primary obstacle. Retracing my steps and trying to open every door became the style of play, and caution was slowly thrown into the wind. As this continued, I would get even more powerful, to the point where I always had plenty of rations and firepower to defend myself against any aggression. The game world opened up dramatically, and I had many more options. This made finding the correct place to go difficult, but getting there wasn't. Whereas before, being caught by the enemy had significant ramifications, these ramifications were lost as I progressed through the game. By the end of the game, I was a walking tank. I killed the last handful of bosses without breaking a sweat. I escaped easily. I conquered Metal Gear. Normally games get harder as you go, but the core mechanic of the game stays the same. When the core mechanic is no longer necessary, a new way of playing is introduced. Because the game became easy from a survival point of view as I progressed, the way I approached the game began to differ. I'm not sure if this was Hideo Kojima's intent when designing the game; it could just be bad game balancing or even something that happened during the porting of the MSX version of the game to the PS2. My preconceived notions of how the game would play were shattered, however. That's what ultimately made me enjoy the game so much; it did what I didn't expect it to do. [Manveer Heir is currently a game designer at Raven Software. He updates his design blog, Design Rampage, regularly. He is interested in thoughtful critique and commentary on the gaming industry.]