Thinking about scary games without monsters in them.
I think my current idea is for a 2D game rather than a 3D game - 3D models, sure, but a 2D playing field. The reason for that is because I want to radically change the scope of the game.
In most games, the areas are scaled-up versions of real life. This is because realistically-sized rooms and hallways feel cramped and are difficult to maneuver in. Even in horror games with cramped environments, such as Dead Space, it's still all scaled up.
I got to thinking: how could you scale it down? How could you make a game where the interiors are actually more cramped than real life?
Well, the easiest thing to do is get rid of the 3D and make it 2D. That lets players see the whole environment around their character and, in turn, lets them understand the layout of the room even if it is cramped. Since we're not using monsters, we don't need to hide monsters off-camera. No loss there. It also gives us an additional bonus: it lets the players be aware of their character's full body in a very precise way. An over-the-shoulder 3D view makes it difficult to determine your exact center of balance, the exact position of your feet, the exact range across the gap.
This is important because what we're doing with this game is making the "platforming" into "slithering". The jumping is rarely needed and kinda dangerous.
I'm thinking of kind of a "slurpy" control, something that feels more like controlling a blob of slime than a person. So you'd just hold your mouse above her head, and your character would smoothly grab opportunities to ascend - starting with the desk and moving easily on into the air gap above the room. Shloop, you're in the air gap. Keep moving, though, because the weak plastic grate that holds the ceiling tiles will steadily buckle under your weight.
The movement should feel easy and "clingy". For example, if there's a pipe across a gap, you can just hover your mouse over the pipe and she'll grab it and shimmy easily along - the low gravity helps. If there's a mostly-closed bulkhead, sweep your mouse beneath and she'll slither beneath.
This isn't to say there are no challenges. There are loads. For example, what if there's a gap beyond the bulkhead and a ledge on the far side of the gap?
Well, you have a few options. One is to just try to slither across the gap - she'll gamely reach across for the ledge and, hey, if she can reach it before her center of mass is over the pit, no problem!
Another is to pull her upright on the gap side of the door and then have her jump. Jumping is accomplished by right-clicking. When you release the click, she jumps towards wherever the mouse point is. This is important to master, because it happens on release instead of click. This is critical because if you move your mouse over to the ledge and then right click, she'll already be reaching for the location and falling into the pit. So you right click on her as she clings to the door, then drag to the ledge, look at the traced path, and let go if you think it'll work out.
Challenges of timing exist, too, and the right-click jump is important for them as well - because it's a dash if there's no jumping to do. So there's a steam vent? Right click on her, drag past the steam vent, then wait until the vent stops steaming and release. It's also important for building up speed: if there's a big gap just past the steam vent, you'll want to right click AGAIN on the far side of that hole before she finishes decelerating from her dash. If she decelerates, she'll just do a standing jump instead of a dashing jump.
You can see where some challenge is beginning to arise. However, this takes place in a complex world that you're trying to escape and/or repair. We haven't even mentioned the left click yet. The left click grips (if held) or interacts/obtains (if clicked) or drops (if clicking on yourself while carrying something).
For example, if you find a broom, you can grab it by clicking. Now you'll cart it around. By holding the left click, you can stop in your tracks and, just like with the right click, you can move the mouse without moving the character. It does, however, move the broom! So you can poke around at whatever you can reach, or jam it into a crevice so you can walk across it, or whatever. By right-clicking while holding the left button, you'll fling the thing you're holding at the target, allowing you to do some long-range interactions or just royally jam it in. Tapping left-click on yourself will drop the broom.
Alternately, there's a cord whipping by. Left click and hold to grab it and get taken for a ride. There's a console nearby. Left click to use it, or left hold to hack it. There's a door. Left click to open it, or left and hold to press up against it and listen.
There are many topological challenges here. Your body is not made of goo - it has a size. So you might find a gap too small to fit your body through, but large enough for your hands. What can you do with it? Well, you can interact with things on the far side. You can throw things through. You can push a broom through and whack at things on the far side.
More complexly, there will be "tight" gaps. These are gaps you can get most of the way through, but then your butt (or toolbelt, whatever) gets stuck. You can only get through by then dashing, and the result is that you karoom into the space beyond in a predictable but uncontrollable manner.
It's not just topological challenges. The starship is a starship, and therefore has many complex things happening. You can run into areas where there is no air, areas where surfaces are burning hot, exposed steam venting, electrical shorts, even areas which have drifted apart due to the damage. But, in turn, you can use the devices of the starship to help you - consoles to open doors or activate machines, controls to let you use cranes, screens to let you seal areas, redirect power, restore airflow, seal hull breaches, cut off fuel... The big idea is that the player can build ships and then try to escape or salvage them when things go south. The devices in each kind of module are an important part of how it will interact with the disaster.
But no monsters.