In the game, theres a substance called source which is used in building pretty much anything, from walls to advanced, possibly sentient clockworks. The people who build with this source are called Archineers.
The story begins very traditionally as we are introduced to the protagonist, Lock. He lives in a small seaside village with his sister, Emi, and his grandfather, Tobias. He's an orphan because his parents, both Archineers, died in a war when he was young. An injured Archineer shows up and the village is soon invaded by clockworks. When Emi goes missing, Lock sets out to find her, ending a war and saving the world along the way.
The majority of the game consists of protecting source wells and people from waves of clockworks. Gameplay is divided into days, and each day typically consists of two sections: Building and Battle. In the Building section, players are given two to three minutes to set up the usual defences: walls, turrets, traps and the like. The Battle section is where the Action Game elements come in, as players fight clockworks directly and repair defences in real time to fulfill win conditions, which are usually surviving for a few minutes. Some others include defeating boss enemies or capturing enemy source wells.
This game provides examples of:
- Applied Phlebotinum: The "source". It's supernatural in origin and apparently gathered from the ground. It floats around as blue, flame-like gobs and is apparently what keeps advanced machinery and talking robots running. Also helps when trying to build walls real quick.
- Artificial Human: All the villagers from Lock's hometown are revealed to be clockworks except Tobias. This includes Lock and Emi, although Lock is infused with a soul.
- Creating Life: It's stated at the beginning that Agonius' goal is to create life from "source". He succeeded... sort of.
- Cutscene Incompetence: Isaiah is supposedly a high-ranked Archineer and is invincible as an in-game ally, but is badly beaten up by some low-level Mooks at the beginning of the game. This arguably helps to sell it midway through the game, when Lock becomes suspicious of the Archineers and begins to doubt whether Isaiah's discovery of his village was accidental after all.
- Cutscene Power to the Max: While Heathern is also invincible and very capable in game, she One Hit Kills several high-level clockworks in a row in a cutscene.
- Unfortunately, she pushes it a bit hard and cycles over to Cutscene Incompetence when it's time for a boss fight.
- Developer's Room: Only accessible after completing the game, and even then the player has to go through a chain of arbitrary events at random locations. (Apparently popping a bubble allows you to activate a source well. Or something.) Lampshaded when the first guy in the room accuses you of lying if you say you didn't look for instructions online. And then he kills you.
- Dark Is Evil: Played straight with the location of Lord Agony's stronghold, which is imaginatively called "Dark Ridge".
- Doomed Hometown: Of course. Demolished at the very beginning of the game. Good news: no one actually died. Bad news: It's because they were all robots.
- Easily Forgiven: Even if Lock did save the world, he kind of still killed Kenan. He is brought before the king but he's let off scot free. Strangely, the king doesn't even make reference to his crime. Lock says he'll accept the consequences but the king just asks Lock whether he has come for answers and reminisces. The implication is that the king was well aware Kenan was a loose cannon where Jacob was concerned and doesn't blame Lock for defending himself.
- There's also the possibility that the King didn't want a repeat of last time he exiled Agonius.
- The Engineer: Lock, who's also The Hero in an unusual case. Mostly due to the setting though, as Archineers are pretty much wizards in this world.
- Extranormal Institute: There seems to be classes held at the Archineer Hall, where recruits are presumably teached a mixture of engineering and the art of applying phlebotinum.
- Gameplay Ally Immortality: When Isaiah and Heathern play as allies in game, they will actively fight off clockworks and won't even get a scratch. Nameless Kingdom Force redshirts, unfortunately, don't get covered by this and will die fairly easily if not protected.
- "Get Back Here!" Boss: The boss of The Fallen Crypt is a beefed-up Clockwork Phantom that spends most of its time circling the map while invisible and does not engage in battle unless Lock finds it. Another boss, the Sapper, is a powered-up burrower who tries to escape the map; he's not that tough, but the trick is to keep up with him and keep him from fleeing the map while he runs past gangs of lesser mooks. Both battles boil down to a cycle of chasing down the boss, beating on them for a bit, then backing off to recover health.
- Heroic Sacrifice: The ending implies that Lock gave up his own soul so that Emi could live, since Clockworks can't truly live without one.
- I Am Not Your Father: Tobias eventually reveals to Lock that he's not actually his grandfather.
- Luke, I Am Your Father: The original Lord Agony, however, effectively is Lock's father.
- Names to Run Away from Really Fast: Agonius, who later took his name to its logical conclusion and called himself Lord Agony.
- Protection Mission: The majority of the missions in the game, usually to protect source wells or other people. What exactly were you expecting from a modified tower defense game?
- Schizo Tech: Lets see, you have highly advanced clockworks and automatic turrets alongside very basic wooden and brick walls. Need we say more?
- Trap Master: Lock, obviously, as a protagonist in a Tower Defense game.
- THREE Aliases One Character: The current Lord Agony and Tobias and Jacob are one and the same.
- We Can Rule Together: Lord Agony offers this to Lock from the beginning. He never actually intends to fight or kill him.
- What Measure Is a Non-Human?: The clockworks are seen to be possibly sentient (with one even making a Rousing Speech at the end), but are of course killed without remorse. This issue is surprisingly not touched upon that much even in light of the reveal that Lock and Emi are really clockworks. By contrast, the rare occasions where you actually fight Kingdom Force soldiers imply that you're just knocking them out cold. Using lightning storms, acid blasts, and explosive cannon shells.
- It does get eventually revealed that the Clockworks really aren't truly alive and can't be without being infused with a human soul. The question of whether destroying them in job lots is okay is never addressed before that.
- Tomato Surprise: When Lock finds out his entire village were robots. And again when he finds out that that includes him and his sister.