1.
Game Design Document
Flux Logic – Light the way
Logline:
Master the physics of light to solve increasingly complex laser puzzles in an abandoned high-tech laboratory
Development Team:
Ryan Gunther-Leece Game Designer
Document version history: v1.0 05/01/26
2.
Game Overview
Flux Logic is a first-person puzzle game with a linear narrative that progresses as the player completes levels. The game’s purpose is to introduce players to novel light physics in a unique and highly visual manner, with the focus being on entertainment and visual fidelity over fully realistic simulation.
The game builds on mechanics of titles such as Portal 2 [1] and The Talos Principle [2] by adding more advanced light manipulation elements and having all elements grounded in real physics. The target audience for the game is teen and adult pc gamers who enjoy problem solving games that rely on skill-based mechanics over reflex-based ones.
3.
Gameplay
The player moves around optical components to redirect and modify beams of light, directing them to the matching targets. Activating all the targets completes the level and opens the path for the player to progress. The players progression gets them closer to escaping the facility which becomes increasingly overrun and decayed as you get further from the core. Puzzles are broken up with traversal sections to match the pacing, longer, more challenging puzzles are followed by longer traversal sections to make the rate of progression feel more linear.
4.
Mechanics
Puzzles are comprised of some limited core elements:
Sources:
Monochromatic laser beam (MLB)
Aligned laser beams (a single beam made of multiple aligned MLBs)
Supercontinuum laser beam (full spectrum, flat power across wavelengths)
Targets:
Small Target (requires focused beam to power)
Large target (requires unfocused/wider beam area)
Light Manipulation:
Mirror (Reflects beam in accordance with Snell’s law)
Filter (Blocks light of specified wavelengths)
Beam Splitter (Splits beam by reflecting half power [mirror])
Diverging Lens (Expands beam – increases divergence)
Converging Lens (Focuses beam – decreases divergence)
Dichroic Mirror (Beam splitter that splits based on wavelength)
Fibreoptic Input (Takes focused beam and directs down fibre)
Fibreoptic Output (Emits beam with same properties as input to fibre)
Frequency Doubling (Halve wavelength of incident beam, aligned output)
General rules for sources:
Sources are comprised of specified wavelengths with specific powers for example, 540nm 3W. A beam comprised of multiple wavelengths simply has multiple wavelength values with accompanying power values. A supercontinuum laser will have a power that defines its total spectrum, the spectrum will cover 100 to 850nm i.e. UV to NIR.
General Rules for targets:
Targets will have a visual indicator of what light will activate them. A part of the targets texture will act as a power meter for example a band round of the targets base that becomes partially to fully illuminated. This acts as an indicator of if the target is powered.
General rules for light manipulating components:
Player movable components can only be slid. Not all components have the same freedom of movement, sometimes rotation maybe locked or snap to certain angles, some components may be forced to slide along a track rather than be freely moved. Certain components such as frequency doubling crystals require thin focused beams to function, others such as mirrors may permit any beam shape.
General rules for the puzzle optics system:
All optics operate on a flat 2D planes at a standardized hight from the floor below them. Multiple planes per level are permitted but direct interaction between planes using the player movable components is not, only optical fibres or level specific optical paths allow this.
A collimated beam is taken to have exactly zero divergence. Divergence can only be altered by lenses.
The displayed colour of a beam is calculated using the following process:
List component wavelength and power values e.g. 400nm – 10W, 600nm – 5W etc.
Convert power to perceived tristimulus (x,y,z) values i.e. relate to human colour perception.
Sum the inputs to generate single x,y and z values
Convert to sRGB and normalize to account for non-displayable colours (values less than zero or greater than 255)
Output colour as a Vector 3 and multiply with the beams emissive value.
The emissive value is calculated using the following process:
Convert optical power to luminescent flux i.e. Watts to Lumens
Calculate beam sectional area using width from centre (radius)
Divide luminance by section area and multiply by a constant
For divergent or convergent beams, the emission is dependant on distance from source i.e. as it is calculated from cross sectional area and the beam forms a cone, change in distance from source will result in a change in emission intensity.
Character actions:
Crouching will bring the player camera in alignment with the puzzle optic plane.
Holding the interact button whilst aimed at a component will allow it to be moved.
Whilst aimed at a component, a rotate button will cause the component to rotate in the specified direction.
The player will come across environmental hazards that force certain movement and at times become a puzzle element. Some environmental hazards may be controlled by the player; these interactions will be done using puzzle elements only. Examples of typical hazards include pitfalls and high-powered lasers.
The player takes damage from hazards but recovers full health in around 2 seconds, hazards such as pitfalls trigger instant death. There is no visible health bar.
Upon dying the player is reset to the start of the level but all other elements remain unaffected by the death.
Saves and options:
Player progress is saved upon level completion. Reloading the game will place the player at a given level start with all components reset. Upon completion of the game levels are unlocked and become selectable.
5.
Story and Narrative
Backstory:
The player awakens to find themselves trapped in heart of an abandoned laboratory
No backstory is directly provided to the player via text or narration
The laboratory is high tech and clean however it has been long abandoned and is slowly decaying and being taken over by nature
The decay is more extreme toward the outer parts of the facility which the player reaches as they progress
Plot:
The game is puzzle focused so the plot is limited
Player finds themselves trapped
Player learns how to use components and solve puzzles
Player traverses abandoned facility
Player escaped facility
Player is free
6.
Game world
The world is broken down into three separate types of location:
Inner laboratory:
The inner laboratory is fully operational and intact
Surfaces are clean
Metal, glass and concrete
Colour pallet is limited, and colours are visually distinct (there is no bleed)
Lighting is fully functional in this section and even
Main facility:
The main facility has seen varying levels of decay
Rust, stains and dirt are common
Colours bleed, faded and patchy paint
Sharp edges, dangerous, uninviting
Parts of the facility are broken, fallen pipes, holes in walls etc.
Water and oil leaks
Sky may be visible very far above player
Darker mode uneven lighting, hard sources instead of soft
Outer Facility:
Outer facility has organic matter growing over elements from the main facility
Decay and breakdown of structure is far greater
Edges are smoother and softened by earth and vegetation
Sunlight becomes prevalent
Algae and moss cause the world to look cleaner and more inviting
Shift toward green and natural colour pallet and away from strong block colour
Transitions:
The transitions between these sections are slow and blended. The idea is to imitate nature taking over an abandoned building in real life. The transition is not always linear, sometimes a hole in the ceiling may lead to vegetation growing in an otherwise intact section for example.
Most of these changes will become evident to the player during the traversal between levels.
7.
Characters
The player’s character:
The player is the only character in the story
They are human and not editable by the player
There is no screen that shows the player their characters appearance, but they may see their character through environmental reflections
Character is of average height and athletic build
There are no other characters present in the game but some creatures such as birds may be added to help with realism, moths being attracted to the lasers for example.
8.
Levels
Levels can be arranged into a loop:
A simple level introduces the player to a new component
A slightly more complex level increases the complexity of the puzzle
Multiple instances of this new component are added to a longer challenging puzzle that contains a variety of previously introduced components
A new component is added and the process repeats
This is not exhaustive and how new components are added and the spacing between these additions will differ. This loop does decently represent the process though and outline for puzzles will have an oscillating difficulty and duration to them as the player progresses.
There is no specific single tutorial or training level, new components are not explained explicitly, and the player must figure out their use by experimentation. Environmental details may offer clues to the player on how to go about solving puzzles, for example being able to see some beams interacting with components in a similar manner to that required for the level through a hole in the wall or across the ceiling.
The objective for every level is to illuminate targets and create a path forward. Progressing to the traversal to the next level counts the level as completed.
9.
User Interface
Visual system:
During gameplay there is typically no HUD but hovering over an interactable object will display icons that show what actions are available to the player.
When controls are first introduced to the player a graphic popup will display the relevant control key binds.
The menu system consists of a title screen that plays a long but looped animation which displays the games title, new game option, load game menu and settings menus.
Load game gives the option to continue, or level select if available.
Settings:
The settings menus contain options for:
Audio:
Master volume
Sound effect volume
Music volume
Graphics:
Screen resolution
Field of View (particularly wide range)
Various quality settings
Controls:
Custom key mapping for all controls
Controls:
Standard PC controls:
Walk forward W
Walk backward S
Strafe left A
Strafe right D
Jump [Space]
Sprint [L shift]
Crouch [L Ctrl]
Interact [Left mouse button]
Rotate left Q
Roate right E
Audio:
Music will take a similar approach to Minecraft[1] with a minimalistic approach with tracks triggered by certain levels.
Sound effects will include components being slid or rotated and environmental elements moving as well as the players footsteps. Some unique effects may also be used for things such as rain entering through the ceiling. Notably lasers do not produce any sound, but a laser pointed at a surface may, for example a popping sound accompanied by a smoke animation if directed onto concrete.
Visual style:
The UI elements will follow a modern visual style with clean lines and block fill colour for text, where shown as an overlay they will have a high opacity. The colour pallet will be comprised of saturated colours and not contain different shades of the same colour.
[1] Mojang (2011) Minecraft (PC) [Video Game]
10.
Deployment
The game is designed to be downloaded and run locally in Windows 11 [1]. It will be made available via platforms such as Steam[2] or Itch.io[3] (tbd).
[1] Microsoft (2021) Windows 11 [Computer program]
[2] Valve Corporation (2003) Steam. Bellevue, Washington
[3] Leaf Corcoran (2013) Itch.io. USA
11.
Development
The game is built in Unreal Engine 5.7. Depending on features present in new releases it may be deemed prudent to switch to future versions to aid development. Several features added in 5.7 are expected to be heavily utilised hence this specificity being noted.
Version control is managed via Git – repo tbd