The game is made in the visual and gameplay style of 16- and 32-bit shmups from the 90's, and features a synth-based soundtrack with Hyakutaro Tsukumo of Thunder Force V fame as a guest composer. Players pilot the Andraste, an AI-controllednote ship with three weapon types at its disposal, an offense-oriented Smart Bomb attack, and a defensive Burst attack that cancels surrounding enemy bullets, or the Scathach, a ship focused on Homing Lasers and several levels of powerful special attacks.
An Expansion Pack, Devil Engine Ignition, is planned for release. It will include a variety of new features, including an Ignition campaign with 6 new stages, a new ship, and an arranged soundtrack by various high-profile video game music composers. It will serve as the initial release version for PlayStation 4 and as paid DLC for the other console versions. A demo of the first stage of Ignition mode can be played in the original game through a password. Ignition was scheduled for a winter 2019 release, but was delayed due to disputes with Protoculture Games and Dangen Entertainment. As of January 2021, Protoculture and Dangen have agreed on amicable terms for severing their partnership and the release of the update will likely move forward at last.
Devil Engine features examples of:
- Alien Geometries: The final boss is a constantly changing and moving series of geometric shapes.
- Antagonist Title: Devil Engine is the game's Final Boss.
- Anti-Frustration Features: If you use a Burst during an "EMERGENCY" screen, your multiplier will not reset. This is handy for using the Burst to change a weapon power-up to another weapon right before a boss fight.
- Big "NO!": The game gives you a textual one if you uncover a Proty only to kill it by shooting it too much."OH NOOOOO!"
- Boring, but Practical: The homing shot. Yes, it has the traditional tradeoff of dealing weaker damage than Spread Shot and laser weapons, however it is capable of twisting into angles that the other shot types cannot hit, giving it plenty of utility in Stages 1 and 3 in particular.
- Boss Warning Siren: When you approach a midboss or stage boss, "EMERGENCY" appears in large-point font with red High-Tech Hexagons behind it, while a brief klaxon plays.
- Bullet Hell: Downplayed for the most part; only a few bosses spit out particularly dense patters, the Final Boss in particular. Played straight on Expert difficulty.
- Continuing is Painful: Losing a life ends your multiplier and decreases your shot power. Dying in quick succession will leave you with practically a peashooter.
- Damn You, Muscle Memory!: On Expert difficulty, the Proty locations are mostly different.
- Difficult, but Awesome: Scathach is trickier to use because it relies on its Homing Lasers for scoring, and those lasers require proper positioning to hit their targets quickly enough. Master it and you'll amass points and thus extra lives much faster than the Andraste can.
- Earn Your Bad Ending: The worst possible ending is achieved by clearing the game on Expert. The Devil Engine sets the Earth ablaze and wipes out all of humanity.
- Earn Your Fun: Modes, extra continues, and other features are unlocked from points earned over all runs. In fact, Easy difficulty needs to be unlocked in this manner.
- Easy-Mode Mockery:
- The difficulty levels come with one-line descriptors that are chosen at random, with the Easy descriptors often being mocking in tone. Furthermore, playing on Easy will stick the words "EASY MODE" in purple font to the top left corner of the screen (whereas Hard and Expert do not indicate your difficulty during gameplay)."Kid's mode"
"Why don't you challenge yourself for once in your life?"
"What's the matter, scared?"
"Ehhhh!? Easy mode!?"
- On a less-humiliating note, there are less bullets and enemies in Easy mode, which may seem like an obvious boon but also means less opportunities to earn points (which are needed for bombs and extra lives) and you can't rebuild your multiplier as easily after a Burst.
- The difficulty levels come with one-line descriptors that are chosen at random, with the Easy descriptors often being mocking in tone. Furthermore, playing on Easy will stick the words "EASY MODE" in purple font to the top left corner of the screen (whereas Hard and Expert do not indicate your difficulty during gameplay).
- Every 10,000 Points: You get an extra life every 50,000 points.
- Freeze-Frame Bonus: On some screens, there is a split-second static screen transition with randomly-chosen text in the middle. Some of the lines include:"Incoming game"
"Please insert disc 2"
"Quickly fixing whatever broke"
- Genre Throwback: The game is designed with a lot of inspiration from 90's shmups, so it's relatively light on the Bullet Hell compared to its contemporaries and the visual style is focused on space military machines.
- Harder Than Hard: Expert difficulty (above Hard), which is unlocked with Lifetime Score, or reached as a 2nd loop after clearing the game on Hard difficulty. Somewhat downplayed, in that Hard is the default difficulty.
- High-Tech Hexagons: The Boss Warning Siren screen features them.
- Hitbox Dissonance: Despite not exactly being the most bullet-dense shooter, the game is still kind enough to give you a small hitbox in the center of your ship sprite; the hitbox can be made visible with no penalty in the options menu.
- Stage 3 borrows a lot from Stage 2 of Thunder Force V, having the player start off over a jungle before descending into the thicket of trees.
- Stage 4 has a high-speed over-the-ocean cruise similar to Stage 1 of Thunder Force IV, followed by a segment through a fleet of battleships like in Stage 3 of that game.
- The Final Boss's final attack is pretty much just one of Shinki's attacks from Touhou Kaikidan ~ Mystic Square except horizontal. The developer admits as much.
- One of the available filters changes the color to match ZeroRanger.
- Idiosyncratic Difficulty Levels: Not the difficulty names themselves, but each time you get to the difficulty select screen, each difficulty level has a randomly-picked one-liner, with the lines for Easy often being negative in tone.
- Kaizo Trap: A minor example; in stages 3 and 5, after defeating the boss and even during the stage result screen, it is still possible to ram your ship into terrain and die if you are careless enough.
- Macross Missile Massacre: The bomb for the Spread Shot weapon fires a volley of missiles in front of the ship. The Homing bomb does the same, but with enemy-chasing missiles.
- Nintendo Hard: Even on Easy, the game is a legitimate challenge, mitigated only by a limited allownace of continues per run that increases as you build up Lifetime Score.
- Non-Indicative Name:
- The lowest two Difficulty Levels are labeled "Very Hard" and "Very Easy" on the difficulty select, even though difficulty levels labeled "Easy" or "Hard" on the same screen are not available; in other screens (such as ranking screens), the difficulty levels are simply called Hard and Easy.
- The bomb attack is this on two levels. First, it isn't actually a bomb-based attack; it's either a Macross Missile Massacre or a pair of supplementary lasers. Second, unlike Smart Bombs in other shmups, it doesn't provide any sort of invincibility or bullet-erasing.note
- Scenery Gorn: Stage 2 starts off with a beautiful "Neon Metropolis". After passing through a tunnel to fight the midboss, you emerge to find enemy ships in the background bombarding the whole place.
- Scoring Points: Shooting enemies in quick succession builds up a combo gauge, and the multiplier increases by one when the combo gauge is full and subsequently reset, while not hitting enemies causes the multiplier to slowly decay. At the end of every run, the player's points are pooled into a "Lifetime Score" that is used to unlock many gameplay features. The scoring scale is fairly low; getting 1 million points is quite difficult without completing the whole game and milking lots of bullets with your Burst.
- One of the random lines shown when switching pages on some screens (like the rankings screen) is "Ships do their best now and are preparing. Please wait warmly until it is ready."
- Lines describing (Very) Hard difficulty:
- One of the lines for (Very) Easy difficulty is "Perpetually awakening the continuing struggle."
- Lines describing Expert difficulty:
- The default high score names list includes:
- One of the bullet appearance options is called "Pink Sweets".
- One of the unlockable options is called "European Extreme".
- When you start a game, the Andraste's bootup UI is shown. It shows, among other things:
- The large text on the boss warning screen reads "EMERGENCY", like in Thunder Force III.
- In Ignition, sometimes one of the hexagons will have the "WARNING" text replaced with something else:
- Smart Bomb: Two types, in fact:
- The Bomb button fires out a high-powered attack that is dependent on the shot type you currently have. It is mainly for bursts of damage; it does not offer any defensive capabilities. Every 5,000 points you gain an extra bomb.
- The Burst button is a more straightforward example of this trope, canceling most types (but not all!) of bullets around your ship. This will expend your entire multiplier, but cancelled bullets will build your multiplier back up.
- Spread Shot: One of the three weapon types you can pick up with weapon power-ups.
- Stuff Blowing Up: The unlockable Hot-Blooded option causes enemies to generate more explosions when destroyed.
- Take That, Audience!:
- One of the continue "hints" informs you that "milking bosses for score is lame."note
- Another hint tells you not to play the game in tatenote because it will "look weird".
- Title Drop: The final stage is called Devil Engine, which is also the name of the final boss.
- Trial-and-Error Gameplay: The game is very heavy on memorization much like shooters of the 90's, expecting you to learn how the various enemy attacks and traps work instead of just transferring your skills over from other shmups.
- Zero-Effort Boss: In Challenge mode, the Final Boss is a stationary Andraste that does nothing and all you have to do is ram your ship, an enemy ship, into it.