Long ago, before SNK was known mostly for their fighting games, they dabbled in a variety of genres, including shooters. Prehistoric Isle in 1930 is one of them, released before their Neo Geo system. As the title implies, it's not the usual generic space battle, but something much more original. The story of this game combines two famous myths: the disappearances of ships and aircraft caused by the Bermuda Triangle, and the existence of a "lost continent" where dinosaurs, cavemen and other remains of the prehistoric era still live. The protagonists are a couple of pilots that, during the investigation of said disappearances, stumble upon an uncharted island that they dub "Greenhell Isle", after they discover that it's full of murderous ancient creatures.
Their mission lasts five stages and starts above the island's jungle and waterfalls, then a battle in the skies above it (the shortest and most linear stage of all), and after that a trip through the canyons and caves of the isle. Then the biplanes inexplicably turn into submarines for what is probably the best part of the game: a journey among all the shipwrecks under the waters near the isle, with all manners of strange sea creatures popping up from and around the rusted ship carcasses. The last area is set in a huge volcanic cave, that culminates in a battle against a gigantic T. Rex... the very same one from the title screen, in fact.
Almost each stage has a mid-boss (stage 2 is an exception) and a boss, all preceded by a warning and some data: their species' name on-screen and their height and weight. They're not really accurate, but it doesn't matter when the Allosaurus roars like Godzilla and the so-called “Unknown Dinosaur” looks more like a mutant, flying, fire-breathing whale than anything. Defeating them is quite satisfying because they blow up into lots of meaty chunks while the screen flashes madly; a darkly amusing touch is that, whenever one of them catches the biplane with its jaws, it doesn't explode as usual, but instead gets munched, crunched and spat out.
Among the beasts there are also annoying neanderthals that can climb onto the biplane, making it hard to control, and you can't shake them off, just wait for them to fall; usually, if more than one of them clings to the plane, a life is lost. They also throw hatchets every now and then and endlessly spawn from little huts that have to be destroyed. To continue with the dinosaur theme, the power ups are found in floating eggs that need to be cracked or else they'll become just another deadly obstacle. The most common items are "S" icons for extra speed, dollar signs for a little extra score, and "P" icons. By catching the "P" icons, the plane gains a pod that, similarly to R-Type's own Force, can be used as a shield against enemy shots and a ram to destroy smaller baddies; unlike R-Type, however, it can't be thrown and doesn't need to grab additional icons for different shots.
The main difference is that the pod's weapon changes according to its position relative to the plane: pushing the second button will rotate it clock-wise around the plane and each cardinal direction provides a different kind of shot. For example, if the pod is right above or below the plane it will shoot walls of flame that bounce on impact, the lower diagonal directions drop bombs on the ground, putting it behind the plane leaves floating mines that explode after a while and so on. It's a novel and interesting idea, and it adds a minimum of strategic thinking to an otherwise basic and straight-forward shmup. Other power ups not mentioned before are a temporary shield, an icon that turns for a limited time all weapons into powerful ring beams that bounce off every surface, and a smart bomb that, however, detonates 5 seconds after having been picked up, making it not too useful.
There appears to be a bit of dynamic difficulty as well: the more P icons you collect, the more powerful all the weapons become, but the enemies become more aggressive and begin to shoot bullets. And there lies the problem common to many shooters of the era: the pod's loss or destruction (unlike R-Type's Force, it can be destroyed) makes the difficulty unbalanced, given that the standard shot is very weak and can't be improved. Especially in later levels it also equals to death, since the pod is essential in fending off the popcorn enemies that come from every direction. You can't rely too much on the eggs either, since they give randomized bonuses.
Despite this, however, the game has aged well and remains enjoyable to this day, with the pod's multiple weapons and the designs of the levels giving a chance to experiment different play styles. The graphics are suitably colorful, detailed and varied for the time and the enemies show a degree of wacky creativity, with things like leaping giant trilobites, zombie pteranodons (!), giant bats that carry cavemen and formless blobs that appear suddenly in the underwater stage. The BGM are also nice and give the stages a sense of urgency that goes well with Prehistoric Isle's general themes of adventure and escape.
In December 2011, SNK made it, among other of their older titles, a part of the Minis, a series of budget games under 100 Mb available for PS3 and PSP on the PlayStation Network's online store. It was a basic emulation with no enhancements or other differences outside the removal of the simultaneous two players action, since it would've been impossible on the PSP.
This game's ending is also infamous: after having defeated the last boss and escaped from the volcano, the biplanes get to a bigger cargo plane, which is then swarmed by the basic pterosaur mooks and destroyed, while a caption states that the island remained a secret... so basically there was no point to the game at all. This kind of downbeat conclusion was common in early SNK titles (see also: SAR - Search and Rescue, Beast Busters, Cyber-Lip) for some reason.
Exactly ten years later, Prehistoric Isle received an arcade sequel for the Neo Geo. It was developed by Saurus, who was previously known for their Shock Troopers run-and-gun series, and published by Yumekobo, who had previously worked on Pulstar and Blazing Star. Just like many sequels that happen several years after their predecessors, this game doesn't have much to do with the original. For starters, there's no island, and the dinosaurs are attacking a modern day city, so there isn't much prehistoric stuff either. Only a couple of stages actually deal with the beasts attacking human settlements though, so it's not even the Godzilla-esque experience the intro seemed to promise. The biplanes have been replaced by modern attack helicopters, which counts as a plus since shoot-em-ups, and video games in general, that feature choppers are still pretty rare.
The only thing that this sequel seems to have in common with the earlier game is the presence of a shorter and more linear stage, that ends with an easy boss: the same yellow flying reptile that appeared at the beginning of the first stage, looking intimidating with its fire breath (that it never uses again) but being actually quite dumb and weak. In general, the game seems easier than the first, what with the more powerful weapons and more predictable enemy patterns. It also was turned into a very standard shoot-em-up, removing all the elements that made it stand out. The levels are much more linear and straight-forward. The developers got rid of the multi-purpose pod and replaced it with a more standard weaponry system based on icons that switch between two kinds of power up (straight/spread shot) a la Raiden. One can, though, keep the shoot button pressed and move the lever to change the shot's orientation.
There's now a secondary shot (various kinds of missiles) and smart bombs have also been added, even if they're more like very powerful beams. The scoring system has been revamped as well: when the weapon's level is already maxed out, picking another icon will start a score multiplier that lasts a while, letting players rack up huge amounts of points. Destroying swarms of enemies or big ones also releases star medals, which are counted at the end of a stage for yet another dose of points. A big score bonus is also given for completing a stage without dying.
Every now and then you will come across people that need to be rescued by picking them up and carrying them to the Blue Cross helicopters that show up. There are also sequences where the scrolling stops, the command "Defend people!" appears on screen and you have to let these people get on board of the rescue choppers without having them killed by the dinosaurs; in turn, some of the survivors will shower you with weapon, missile and bomb bonuses.
All the graphics are pre-rendered 3D turned into 2D sprites, which was common at the time but looks quite dated today, making all the vehicles and enemies seem like plastic action figures. ("The Computer Age Versus the Jurassic Age!", proclaims the game's flyer.) Among them there are a bipedal horned kaiju creature, turquoise sand worms, a fire-breathing dinosaur skeleton that could be a Joe & Mac reject and giant multi-eyed bugs that are yet another homage to the Ohmu from Studio Ghibli's Nausicaa. To say nothing of the final boss: a squid-like alien monstrosity several screens long that wouldn't be out of place at the end of a Darius game, but looks especially bizarre here. Don't worry about another cruel game ending sequence, though... but simply because there's no end to speak of, only the credits.
Prehistoric Isle 2 is a campy, goofy title: the booming, wannabe-epic score contrasts with the rainbow-colored reptiles that spit fire, beams, bubbles and energy rings, and the flying enemies that have crates (for power-ups) hanging from their beaks. The people speak with little wacky noises and balloons that say HELP in big colorful fonts and OH NO! when the helicopter that carries them get destroyed. Everything gives huge amounts of points as well. It's a decent, if bizarre and repetitive, shooter on its own, but compared to Aicom/Yumekobo's other shoot-em-ups, it feels pretty underwhelming. It was never ported anyone either, not even as a Virtual Console release, so it's mostly remained forgotten.