ID:1981235
 
So, we had 0-bit games, now let's take the next evolution, 1-dimensional games.

I'm considering making this into a contest with a prize, but I'm interested in seeing what sorts of things people would even be able to accomplish fullstop.

The rules of the environment would be that the map is a line, horizontal or vertical doesn't matter, but it must be soley a line. Since it's one-dimensional, your icon_size must be 1 as well, although that makes working on the map in the map editor a major pain in the arse, so I'll allow 32x32 size icons so long as they're only solid blocks of colours. That effectively means you have a bunch of "big" pixels. No animations are allowed, and that includes alpha, since alpha would "emulate" the Z dimension. You can have two things ontop of each other, but you can't use alpha to differentiate them. TECHNICALLY colour also would count as different dimensions, but you can't have a game in which there's no way to differentiate between things, though I'll probably give bonus points if you manage to accomplish that. I'll also allow drawing letters on the icons, or even words, so long as they're used for game purposes and not for position purposes. Again this is technically another dimension, similar to colour, but since games would be difficult to create without it, I'll allow it with bonus points for not using it.

What sort of games are even possible in this environment?

Kaiochao suggested Guitar Hero, which is possible in 1D.
(These ideas were made under the rule that the screen can only be a 1-pixel-wide line of colored pixels)

The Sky is Falling: 1D
Random pixels fade to black that you have to avoid being near

1D Infinite Runner
Obstacles constantly move through you and you have to hold a key as they do to avoid dying

Guitar Hero
Notes move through a point where you have to press a key to play the note. The pitch depends on the color, so you have to associate keys on your keyboard to colors on the screen, as well as time your key presses.
Best part about a 1D rhythm game is you could get away with it also having 1-bit color assuming you only tap for one instrument.

When I contemplated this quite some time ago, someone showed me a 1D game that somebody actually made already. It was a platformer, interestingly enough. I can't seem to find it now, but it was cool. You just had to make it to the goal, and obstacles like water and moving objects were just differentiated with color. If I recall, the jump had your "character" change shade a bit and play a jump sound until changing back and playing a landing sound a bit later. It worked really well and actually felt like you were jumping in 1 dimension. Or something -- I'm not sure you can call it jumping in only one dimension.

On the subject of next evolutionary steps, with regard to color, I actually thought of doing the same thing as 0-bit Adventure but with no colors. I guess that'd be called negative-infinity-bit. It would just be no map and only sound.
Since this is here, I'm gonna explain what 1, 2, and 3 dimensional means. It may surprise you guys, but a lot of people don't even know why they're called that.

Dimensions are represented by axes. Having one dimension means either having the x, y, or z(height) dimension.

2-Dimensions is what BYOND is typically capable of, having both the x and y axes to manipulate. BYOND does include the z axis, but it doesn't act as height but rather level. Rendering multiple levels would theoretically allow kinds of 3-Dimensional gameplay, but the engine and mapping system isn't designed for it.

Fugsnarf' game '0-bit' uses no graphics, meaning it used 0 axes.
Well that's not technically true. 2 to the power of whatever the bit is will be how many colors are available. For 1-bit, there are 2 colors available per pixel -- that is, on or off -- as 2 to the power of 1 is 2. 2 to the power of 0 is 1, so 0-bit is 1 color -- that is, just the color of the screen. That's why I said that no color whatsoever would need to be negative-infinity-bit, technically.
In response to Konlet
0-bit describes the number of colors available in the palette.
0 bits gives 2^0 = 1 color.
1 bit gives 2^1 = 2 colors.
2 bits gives 2^2 = 4 colors.
BYOND supports 24-bit = 2^24 = over 16.7 million colors, also known as True Color.

The number of dimensions that can be rendered on the screen is separate from colors.

0-dimensional screen positions could be rendered as a single pixel, if anything (I say "if anything" because the point is infinitely small).

1-dimensional screen positions could be rendered as a straight line of pixels, if anything (the line is infinitely thin).

2-dimensional screen positions would be what monitors these days have by default. Positions lie on the flat plane that is our screens.

3-dimensional screen positions refers to one of: real 3D, where virtual points are represented in real 3D space (we don't have this technology); parallax 3D, where one eye simply sees a different perspective from the other eye, causing the illuson of depth; and then there's normal 3D graphics rendered on a single 2D screen by projection (vector math term).