The story revolves around a hero who awakens in a field, without any memories of who he is or where he comes from. After befriending a magician named Darus and rescuing Princess Lefis of Ark from her crashed airship, he learns that the nations of Samara and Ark have been conquered by tyrants named Nova and Gadiss respectively. The hero is launched into a quest to protect the Princess, free the people from the villains' reign, and discover his identity.
Remarkably for an 8-bit system, the game uses AI control for everyone but the hero, who is the only character controlled directly by the player. Allies can be given orders to attack specific enemies or stay back from battle. It also includes a surprisingly deep plot for its time, coupled with several cutscenes akin to another of Tecmo's NES / Famicom works.
Radia Senki: Reimeihen contains examples of following tropes:
- After-Combat Recovery: Any knocked out allies are revived after battle with 1 HP.
- Artificial Stupidity: Your allies suffer rather hard from this. They don't understand knocking enemies away with their attacks to avoid damage, and will usually remain as close to an enemy as possible even if they are waiting for their attack to cooldown or even if they're a ranged attacker anyway. Haman is particularly bad for this being the only melee AI member, but Leorina is even worse: She uses Haman's melee AI despite being a ranged attacker.
- Badass Normal: The hero is the only party member unable to use Techs. He just stabs everything, over and over.
- Big Bad Duumvirate: Gadiss and Nova.
- But Now I Must Go: The hero has to return to the "real" world in the ending.
- Contractual Boss Immunity: Offensive techs and items cannot be used at all during boss fights.
- Cooldown: Each party member has a "Power" meter that must refill before they can use another Tech. Since it shares the same space as their HP meter, increasing HP by levelling up also reduces the time needed to recharge.
- Death Is a Slap on the Wrist: If the hero falls, you're just sent back to the last time you saved, without losing any experience.
- Disney Death: At the top of the Tower of Water, Haman is seemingly blown up by the boss you just fought. He turns up near Guandia, and eventually rejoins the party when Leorina leaves.
- Distressed Damsel: As common for RPGs of the era, Princess Lefis ends up as this.
- Dream Land: The world of the game, Lemuria, is one.
- Flunky Boss: Veg conjures walking flames, and the Baron Spider is accompanied by Nero and Gestahl. The Final Boss also has an infinite horde of mooks.
- Giant Spider: The Baron Spider, a later boss fight. Smaller (but still large) spider like creatures are encountered as random encounters.
- Glass Cannon: The hero starts off as this, having less defense and HP than other party members, but eventually rounds out into a Lightning Bruiser past mid-game.
- Guest-Star Party Member: Leorina, who joins to help the party save her homeland. Also Saria, before she reveals herself as The Mole.
- Harmless Freezing: Everyone in Guandia is frozen solid, but they're perfectly fine after you defeat Sol and unfreeze the city. Sol's ice blasts do cause damage over time to your characters while they're frozen.
- Heel–Face Turn: Saria ultimately rebels against her father Nova.
- Hello, [Insert Name Here]: The only thing the hero can remember at the beginning of the game is his name. No matter what you choose, it turns out to be a Meaningful Name in-universe.
- Heroic Sacrifice: The Hyupos turn themselves into trees to replace the trees in Zenobia's forest.
- It is implied that Saria dies warping the party back to the Fitzkerard.
- Hoist by His Own Petard: The Master of Dreams ends up devoured by the Nightmare Monster he brought into Lemuria.
- Infinity +1 Sword: The Lemuria Sword. Remarkably, you're given this sword right before The Very Definitely Final Dungeon.
- Laser-Guided Amnesia: The hero suffers from this. It eventually clears up.
- Money Spider: Averted. Most monsters will drop Prize items, which can be used as items or sold for a fair amount of money.
- Not the Fall That Kills You…: The protagonists can jump down pits just fine, but party members or enemies alike are instantly killed if they're knocked into a pit in battle.
- Palette Swap: Both Saria and Midea share Darus's sprite, colored pink instead of yellow.
- Plot Device: The eight treasures of the cities of Lemuria. They're not the secret to unlocking Radia Tower, but how to build the ship to reach it.
- Punched Across the Room: All attacks knock enemies back, which is vital to avoiding damage. Gadiss' attacks will launch your party members all of the way across the room.
- Real Men Wear Pink: Haman is clad in pink armor.
- So Long, and Thanks for All the Gear: Leorina. Saria is an odd case, as her stats and learned Techs pass over to Midea.
- Squishy Wizard: Saria and Midea.
- Star-Crossed Lovers: Two pairs: The hero and Lefis and Darus and Saria.
- Too Awesome to Use: Balls of Life, which fully heal the entire party and restore everyone's Tech points to full.
- Trauma Inn: The heroes can sleep in any bed they encounter to fully restore their strength and save the game. Even in enemy occupied areas, they'll have a good night's sleep undisturbed.
- We Cannot Go On Without You: The hero falling in battle immediately returns you to your last save point.
- Wham Episode: The appearance of the Master of Dreams, right after you've finished off the Big Bads and apparently saved the day.
- You Can't Thwart Stage One: The bad guys are going to get the eight treasures and the spell to unlock Radia Tower, despite the protagonists' efforts.
- Zero-Effort Boss: The two Samaran lackeys who attack Saria rarely even attack during the battle against them. Justified, as they're trying to get Saria into your group.
