For gravity change I wanted to add another video as base for brainstorming.
It's a boss battle from the game Gunstar Heroes. The stage is some sort of modern ore cart ride and your cart has the ability to change between left/right wall and floor/ceiling.
Maybe this gives some more ideas which can be carefully stolen and updated/changed

http://www.youtube.com/watch?v=Qq-5Jiq4c9M

Love your last sentence, Firoball

txesml, I must admit I don't fully understand your images.

Took me some time to understand that "column" meant "column" and not "row" (I was looking at rows). But in your concept, the player doesn't change any gravity. Or does he? So wherever you land, the player simply stands upright on that surface?

i know that you already have a bunch of ideas but here is another one

what if the gravity was continually changeing the entire time and you as the player have to be in the right spot at the right time so you do not die. perhaps this could be used for just a level or two where the gravatron device is malfunctioning and will not stop changing gravity.

i also hope you keep the discussions and progress on the forums because i do hope to follow along. good luck!

here's an idea of how we could implement the gravity-changing:
http://www7.picfront.org/token/y4KU/2010/02/03/1753351.jpg
arrow keys for movement, WASD for gravity direction:

1: jump (space key)
2: while in the air there's a slow motion effect. not overdone, but just a tiny little slowmo. press W (only works in the air, no gravity-changing while standing) to change gravity direction. Player turns in the air quickly (slow mo is over) and lands on the top side, because gravity pulled him there.
3: moving with the arrow keys
4: jump (space)
5: player presses D while in the air -> gravity direction change. player is pulled into the pressed direction and lands.
6: player can move on the new surface.

Gunstar Heroes by the way uses double jump for gravity switch. If you jump during the biggest distance to the floor, you will switch to ceiling and vice versa.

By allowing some hysteresis concerning the jump height, this should be very well playable.

These are all very interesting ideas. What do you think about representing the gravity changing objects as magnets? The player would have to orient them properly using some switches on the floor, ceiling, etc in order to prevent them from attracting its body for good. It's just an idea for some of the levels; we need many different ideas in order to take our game to its 100th level without boring the players. Check out World of Goo to see how a simple, repetitive game concept was turned into a great game.

That is right. i though it could open some puzzle chances. Just another idea.

I like your concept. I didn't find the way to solve the gravity custom angle visual identification with a not rotating scenery.

Salud!

Well rotating or still scenery is just a matter of the view angle.
Either you roll the camera so the player always has the same angle -> rotating scenery, player not turning... or the camera is fixed -> fixed scenery, player turning.

I think it is not much effort to change between those two concepts, so it should just be checked what works out better.

Agreed. That part's rather simple, though it will change the gameplay a lot. We'll need to test it.

I think what's more difficult to decide is how we'll manage the whole "gravity-changing" ability.

-The initial idea was that the player can switch gravity up and down, or even left or right.
-I think Georges idea was that the player can't do so by hitting a key, but only by hitting a switch in game.
-And if I understand txesmi (what does your name mean? I can never remember it :P) right then his idea was that gravity does not (only) switch by player action but by moving through special zones that have previously been defined.

Now the question is, how can we combine these three ideas? I really do want to keep the first idea as the basic ability in the game, because if we only use switches then the game is too linear: if we let the player decide where and when to switch gravity, then there might be multiple ways of solving a level.
Of course, switches can still be used to manipulate gravity. For example, switches could be used to add an additional gravitational pull: boxes are sitting ontop of the place where you wanna go to, so you push a switch which makes them fall towards the ceiling and then you can walk to the place where you wanna go, without the additional field affecting you.

As for the regions: Same thing goes. If we ONLY switch gravity using regions, the player actions will be predefined by us. So I'd vote for a mixture. The way you showed the regions they're basically objects that always attrakt the player to be facing them and fall towards them. Superku showed something like that in his prototype.

And Enemies: Can we find a way to make moving enemies NOT kill the player? I always found that annoying, 3 lives, then you die, collecting extra lives... I dunno. That's retro, and we just had a retro contest. Instead, we could make the enemies block the way (large golem-guards?). Or maybe levels where the guards mustn't see you, so you need to switch gravity to make them fall into some dark corridor or something, and then run past.

Story-Wise, I have an idea. Do you remember Angelas World? I'd take a character like in that game as our main character: a small girl. She has to go and find her little brother, who's gone missing. She just happens to have that gravity-switching ability. I don't really think we need an explanation for that. When she finds her little brother (in level 8 or so) you can then play both the characters. You switch by pressing "1" or "2" and when you play her, you can switch gravity, when you play him, you can switch times/ages.
Goal is to get back home, past all the dream-world creatures that the two of them imagine (or that are really there, but only children can see. whatever. I'm thinking of a world that goes along with the background in george's prototype).

The advantages of this two-character game idea:
-it is more difficult (just changing time AND gravity at all times is too easy), because the player must look after two characters at the same time.
-The explanation of the game could be done using dialog between the two, in game.
-We could add a funny twist: the smaller brother sees monsters that the older sister can't see. She'll always say that he's only imagining them and pull him along.
-The two siblings can help each other: he'll stand on a switch to change gravity, while she'll walk and get the rope that they'll need to finish the level.

Sorry, long post...

Well I think it is not that difficult to combine those abilites.
Switches and special regions are more or less the same. One you have to use, the other one you activate by walking - this should be no problem at all to combine.
Later in the game, the player should obtain a gravity switching device, which allows to switch gravtiy at any time. This allows an increasing difficulty throughout the game (limited possibilites at beginning: easier)To limit this option, maybe argument that the batteries of the switcher cannot provide enough power for constant gravity switches and need to recover.
Of course this way a recharge feature could be added, but this might interfere with the time warp idea (power supply was not available ine arlier times). In short we should not focus on the recharge feature for now.

About monsters/enemies: for sure there need to be enemies immune ot the gravity switch, meaning they will not fall from the ceiling but just stay where they were.

To make the player aware of that, there should be some sort of automatic introductions - means as soon as a new enemy shows up the first time, the game halts and an info screen about the enemy shows up.
Same can be done for items and objects.