Air Fortress is a game released in Japan in 1987 by HAL Laboratories, today best known for Kirby and Super Smash Bros. It came to American shores in 1989. Its basic plot will remind you of the ends of some of the Star Wars films in a way: The planet Farmel finds itself threatened by eight mysterious Air Fortresses. The Federation of Intergalactic Powers has thrown all their defenses at the Fortress to no avail. Now, it's been decided that one man, Hal Bailman, will attempt to infiltrate and blow up the Fortresses from the inside.The gameplay of Air Fortress combines two genres, and can be said to be composed of three separate parts. The first part of a given level is a Shoot 'em Up where you're trying to get inside the Fortress in question. On your way, you also want to gather as much Energy and Bombs as possible. These will all come in handy in the second part of the level.In the second part of the level, you're actually inside the Air Fortress in an Action Adventure type of game. This second part of the level can effectively be broken down into two parts in itself:
Denial of Diagonal Attack: The player can only fire left and right, which makes later levels (especially level 6) absolutely infuriating when enemies are directly below you and knocking you back up into the air with projectiles so you can't drop down within reach.
Difficulty Spike: After fortress 4 and again at number 6. Compared to the hell that is navigating level 6's fortress, all of level 7 is considerably easier — the approach only has two squads of moving enemies, and the fortress itself really has only one fork until you get to the Reactor, and both choices ultimately lead to the same place. 8 spikes again.
Engrish: For some reason, the Japanese version of the game has what little text it does have in English. This leads to such jewels as "You have encounterd the 1st 'Air Fortress'" and "On the planet 'Farmel', they had the gloriest days for two centuries..." This may be because supposedly, a very limited number of copies of the original version came over to the States in 1987 as a "test run" for HAL Laboratories to release games in the US. Note that the proper US version has a much better translation.
Excuse Plot: Translation aside, the actual story of the game never really figures into the gameplay itself.
Technically speaking, every Air Fortress after the first is non-linear, but they don't get truly mazelike until Level 4. At this point, the teleporters first become asymmetric — taking a teleporter at Location A will take you to Location A', but even if there's a teleporter at A', which is far from a certainty, said teleporter at A' is almost guaranteed not to take you back to Location A. This especially applies to Level 6. Trying to determine the best path to the Reactor and then your ship becomes a huge part of the challenge in the later levels — no matter how much Energy you grab, just wandering around the Fortresses aimlessly is guaranteed to get you killed, either by enemies or by failing to find your ship in time.
Level 8 takes things to a whole new level of complexity. If you haven't cleared yourself an escape route in advance, you almost need to use speed running techniques to make it back to your ship before the fortress explodes.
Meaningless Lives: The shmup sections in the Japanese version give the player three lives to complete it, but since the player restarts back at the beginning of the stage after each death, there's really no point (even moreso since dying in the infiltration section is an instant Game Over.)
New Game+: A second immediately follows the first. The level layouts are exactly the same, but there are more and/or harder enemies. The level and fortress colors are also inverted and the destinations of most of the warp pipes are scrambled, radically altering your path through each fortress.
Nintendo Hard: The game stops playing around at about Level 4, but gets downright evil at Level 6. The main reason this game doesn't have the reputation of Battletoads or Ghosts N Goblins is simply that it's not as well known in general. This is without getting into the even more fiendish Japanese version, which sends you back to the beginning of the Approach segments every time you lose a life (the US version lets you respawn where you died providing you still have extra lives), and which generally starts you off with slightly less Energy than its US counterpart. How hard is this game? Frankomatic'sLet's Play of the (Japanese version of the) game has him stating that he won't be abusing Save States. By Level 6, he throws this condition out the window... and still fails to beat thelevel. The next video opens with him saying "As you can see, the sixth Fortress got hit with a big 'Fuck You' bomb that fell out of the cartridge, so we can continue."
For reference, this run shows one of a handful of routes known for the level. At the time, it was a different (and faster) route than was in any walkthrough on GameFAQs, although the use of speed running techniques also helped.
Recoil Boost: When Hal fires his weapon it gives him a slight push backward, and a bigger push backward if he is midair, the latter resulting in movement slightly quicker than his normal movement. While this is commonly viewed as a staple speedrunning technique, it can be utilized to gain ground against enemies that are otherwise able to keep up with Hal's movements, either as a means to set up a retaliatory attack or as a retreat.
This technique can be used to easily get out of the reactor room of level 6. The "gravity spikes" at the bottom of the room may prevent Hal from leaving the area at his normal speed unless precise movements are made; propelling himself backward with his gun is the most consistent way to get out in a hurry.
Regenerating Health: To a certain extent — inside the Air Fortresses, pretty much any action (moving, shooting, etc.) will gradually deplete Hal's Energy down to a minimum of 5 (where he essentially becomes a One-Hit-Point Wonder), but if no buttons on the controller are pressed, he will gradually recover any Energy lost this way. However, actually taking damage from enemies both drains Energy and lowers maximum Energy, so getting into prolonged firefights is a bad idea.
Take Cover: The elevator shafts inside the fortresses serve as this, even though enemies will continue to try to attack. In the later fortresses, it becomes important to carefully time your exit from the elevator to avoid taking excessive damage just trying to enter the room.
Timed Mission: From the time you shoot out the Power Reactor you have approximately two minutes to find the level's escape hatch, which contains your ship, and escape the Fortress before the whole place explodes. Exact Time to Failure is averted, but you can judge how much time you have left by the decreasing stability of the environment. Initially, the whole Fortress goes dark; after a short period of time, it begins to quake and rumble; soon thereafter the rumbling gets worse and the lights begin to flash on and off, and finally this intensifies until the explosion occurs and you are completely engulfed in a white screen, at which point the game ends. It is helpful to locate and determine the path to the escape hatch in advance, but not every level grants you this opportunity due to the reactor itself blocking the escape path.
Video Game Flight: Hal is capable of this inside the Air Fortresses. While he is technically capable of unlimited flight, going upward does still temporarily consume Energy like left/right movement does, until it is idled and recovered back.
A Winner Is You: The game has a pretty typical 1987 ending. Which is to say, the effort you go through to get it is not nearly worth the reward.
Your Princess Is in Another Castle: So you've gotten through the whole game, barely escaping from the last Fortress. You sigh in relief, get ready for the ending...and are greeted with approximately "ATTENTION! The Air Fortress has recovered its function. Hal Bailman must return to the Air Fortresses and disable them completely. You are approaching the 1st Air Fortress." At this point, you will either Rage Quit and never play the game again, or become determined to beat the second quest out of spite at the non-ending you just got handed. Note that the Japanese version actually gives you an ending at the end of the first quest, with an "Input these codes to play the second quest" after the fact.