The story takes place in a sci-fi/fantasy western setting, with humanity under attack by a race of shapeshifting interdimensional aliens called CIMA , who attack humans by pulling them through portals into their world and feeding on their hope. There also exists an organization called the Gate Guardians who oppose the CIMA for humanity's sake, mostly acting as glorified bodyguards for travelers. When a train carrying settlers, along with three Gate Guardians: Jester, one of the six most elite Gate Guardians, and two rookies, Ark and Ivy, are pulled through a CIMA gate, and while scouting for a way out, the group is attacked by Pike Nighttrap, one of the Crimson Nine - the leaders of the CIMA. The settlers are scattered all over the CIMA world when the dungeon they're in collapses, while Jester is quickly killed fending Pike off while Ark and Ivy escape, leaving them to spearhead the rescue effort and clear a path for the train to make it's getaway back to the real world.
Along with the typical Action RPG elements, CIMA also incorporates some strategy elements as well. Since Ark and Ivy can't leave the rescued settlers on the train for risk of being attacked again, they end up tagging along with them and have to be protected. Fortunately, only a small handful of settlers take the role of The Load, while most of them have skills that can be utilized in dungeons, whether it's being able to fend off enemies, heal, or pass certain obstacles (for example, one of the pioneers is a small boy who can cross bridges that would crumble under the weight of a full-grown adult.)
This game contains examples of:
- Action Girl: Ivy
- Aerith and Bob: The main characters are Ark and Ivy, the mentor is named Jester, and some of the settlers have names like Yurald, Vanrose, Eberle and Telmia. And then there's settlers with names like Doug and Jean.
- And Now for Someone Completely Different: The player will occasionally take direct control of one of the rescued settlers after they're separated from the group. In the final dungeon, all the combat-capable settlers even get their own boss fights.
- Antagonist Title: The CIMA are the alien invaders, and are outright called the enemy. Averted in the Japanese version, which is called Frontier Stories.
- Artistic License – Religion: Yurald is supposed to be a priest, but is depicted wearing a rabbi's yarmulke.
- Big Bad: Pike Nighttrap, one of the Crimson Nine (the most powerful CIMA) and the effective leader of their Alien Invasion. He and his fellow CIMA feed off the hope of humans and seek to destroy the Gate Guardian heroes.
- Brats with Slingshots: Halley
- Defector from Decadence: Ivy is a CIMA who decided to side with humanity.
- Defrosting Ice Queen: Ivy
- Degraded Boss: Bruton, the first boss of the game, reappears in the dungeon after it as a respawning CIMA nest enemy.
- Eldritch Location: The CIMA world.
- Emotion Eater: The CIMA
- Escort Mission: The entire game. Fortunately, the player is able to issue commands to the rescued settlers, and some of them are capable of fending for themselves and protecting other settlers.
- Eyepatch of Power: Pike
- Eyes Always Shut: Eberle
- Failed a Spot Check: Yurald's ability is to hide nearby settlers from enemy detection.
- Floating Continent: The CIMA world is made up of a series of floating islands.
- Gameplay Ally Immortality: Ivy becomes invulnerable during boss fights. Unfortunately, she also doesn't do anything during boss fights either except follow you around.
- Gameplay and Story Segregation: Even if you park all the settlers in front of a CIMA nest and hack away at enemies until everyone's trust goes into the positives, Vanrose and Doug will still hate you for much of the game.
- Good Old Fisticuffs: Vanrose's weapon of choice.
- Gratuitous English: Genox is fond of this in the original Japanese version.
- Grumpy Old Man: Doug has a fierce dislike of Gate Guardians after one failed to protect his daughter from a CIMA attack. Fortunately, he warms up to Ark and Ivy after a while.
- The Gunslinger: Ivy
- He Knows About Timed Hits: The tutorial Jester gives you in the first dungeon.
- Hero with Bad Publicity: The settlers start out mostly not trusting in Ark and Ivy's ability to take over for Jester in the slightest (it doesn't help that one of them just hates Gate Guardians in general). The player has to spend the rest of the game earning that trust.
- Hope Spot: The CIMA utilize this to feed on humans' hope, offering people they've pulled into their world a way out, and then trying to kill them before they can reach the exit.
- Hub Level: The train acts as one, directly connecting to all the dungeons. It's also where the player can boost the attack and defense of any of the characters if they've rescued Doug.
- Improbable Weapon User: Jean attacks by throwing scalpels.
- Insurmountable Waist-High Fence: The player often finds their path blocked by a column. Not columns plural; a single, skinny column that the characters can easy just walk around most of the time, but instead have to find something to trigger it to sink into the ground.
- Inventory Management Puzzle: Each character can only carry 21 items (16 items in their inventory, and 5 quick-slot items)
- Item Crafting: Done by using crystals called Majesty that are randomly dropped by enemies. Each character (including settlers, but only if they trust you) have their own items they can make.
- It's Personal: One of the recurring CIMA builders is responsible for the death of Doug and Ilyeda's daughter.
- The Little Detecto: Halley and Emmy can find and dig up any buried treasure they walk by.
- The Load: A few settlers have no special skills beyond Item Crafting and only exist to be protected. Telmia is the biggest load of all, ending up injured by the time you find her, and having the weakest defense in the game.
- Load-Bearing Boss: Defeating Pike causes the whole hub world to start to collapse.
- Lovable Coward: Rick. Though his fiance doesn't think his cowardice is all that lovable...
- The Medic: Jean
- The Millstone: Vanrose starts out butting heads with Ark and Ivy at every opportunity and causing trouble, until he eventually learns to trust them enough to go along with their plans.
- In fact, one could argue that he indirectly leads to Jester's death in the first place during his What the Hell, Hero? moment with Ark and Ivy, guilt tripping them into going back to help him, when all they accomplish is distracting Jester long enough for Pike to fatally stab him.
- Mook Maker: Most enemies come from CIMA nests marked by floating crystals.
- Pressure Plate: If there's one thing the game loves, it's pressure plate puzzles.
- Recurring Boss: Pike's underlings are each fought throughout multiple dungeons before they're defeated for good (fortunately, they can shapeshift into a different form for each fight.)
- Sequel Hook: There's quite a bit of worldbuilding in the beginning of the game that never pays off since the game is spent almost entirely in a series of CIMA dungeons. Also, when Pike is finally defeated, he warns Ark that the other members of the Crimson Nine are out there, making it look like Neverland was setting up for a sequel that never happened.
- Spell My Name With An S: Genox is named Zenox, in the original Japanese. Also, Sunfraw, one of the bosses in the third dungeon, is named Sunflow in Japanese (which makes more sense, since it fights alongside a boss named Moonflow.)
- Sword Beam: One item allows Ark to shoot lightning from his sword until he's hit.
- Technobabble: The intro scene consists of Jester and some guy in an underground facility spewing incomprehensible Technobabble at each other before any of it is defined. Majesty? Plug? Base? Singularity? What the hell are you even talking about!? The best part is that the scene is about the overall CIMA invasion and the efforts to combat it, when the rest of the game is only about rescuing a handful of settlers.
- Took a Level in Badass: Rick eventually gets over his cowardice just in time to rescue Diana from a CIMA attack.
- Two Lines, No Waiting: The party is frequently separated, forcing the player to guide the separated characters to a rendezvous point, and then take control of Ark and the remaining party as they get there as well.
- Weapons of Their Trade: Doug's weapon of choice is his blacksmith hammer.
- We Cannot Go On Without You: A party-wide example. If even one character's HP hits 0, it's game over.
- Welcome to Corneria: Parodied in the fourth dungeon, which contains a stock RPG town full of identical NPCs that only say one line apiece, making conversation useless.
- What the Hell, Hero?: Vanrose is not happy with Ark and Ivy leaving Jester behind to fight Pike (even though he ordered them too) and the revelation causes the entire party to lose trust in them.
- Vitriolic Best Buds: Ark and Ivy once the rescue mission starts.
- Elvira and Genox for a villainous example.
- You Lose at Zero Trust: Each settler has a trust meter that goes up and down either because of plot reasons or because the player protected them from an enemy (or conversely, let them get hit.) Settlers that don't trust Ark and Ivy (denoted by a negative trust score) aren't able to craft items for them.
