I think this is a good idea, but ideas like this tend to fail for some reason (i.e. Mayhem's Robot Battles, Scratch's Tournament). Just make sure it really does get updated every two weeks, and you'll be fine, though.

As for some ideas:

3D Game (doesn't have to be as complex as Canthiar's 3D Model or Mayhem's 3D Dungeon Adventure, but it has to look good. Size and rotation effects will be essential.)

Third-person shooter. I see too many first person shooters (mainly because they're so easy to make), let's make some third-person ones. My second project was a first-person shooter, actually =P

Platform Game. Can be based off an engine others created (like mine =P), but has to be fun and has to work.

Also, is this going to be a contest or something else?

the main difference between this and the tournaments is that this is not a competition.  deliberately so.  i think it is just better if people try to solve a problem in their own way without trying to out do each other and hopefully encouraging people to discuss ideas.  this should also fit with the scratch ethos (is that the right word?).
   i like the idea of 3D challenges but maybe not as the first ones.  as archmage mentioned there needs to be a balance of complexity however i do not want it to be too simple.  i think there are just a few incredably skilled users (canthiar, jmgibson, kevinkarplus etc) but i think there is a large number of very capable users and these were the people i was mostly aiming this for.
   i like the idea of starting simpler and making them more complex if people feel that is the right way to go.  firstly i would need to see if anyone decides to take part.
  i thought maybe a challenge could be to make a car with realistic skidding when turning.
thanks for your comments

This could turn up some really interesting things!  It could be a nice idea generator and a good tool for people who want to learn more about programming/Scratch.

I'd suggest that "comments" in the code be a requirement (or at least strongly encouraged). 
This is something that has been suggested as an improvement (something built-in like a tool-tip or "note"), but there's a workaround;  LeBurt did a project using the "Think" block from the looks category to put comments in one of his projects, and this works pretty well.  (He just left the "Think" blocks disconnected from the scripts.)

Definitely interested.

I also have made a game that feels EXACTLY like 3D, but some very supportive comments told me one by one that it wasn't true 3D.

gee, first zee mapping and now matrices! now what are matrices?

here it is http://scratch.mit.edu/projects/JoelP/43263

Last edited by JoelP (2007-10-10 07:05:17)

JoelP wrote:

gee, first zee mapping and now matrices! now what are matrices?

Matrices are used to describe linear equations, keep track of the coefficients of linear transformations and to record data that depend on multiple parameters.

http://en.wikipedia.org/wiki/Matrix_(mathematics)

However martices are beyond the ability of almost everyone at scratch.

Also joelP I looked at your response to my challenge. I think it has an error because I heard it go "Bop" when the number generated was not a multiple of 5.

Last edited by archmage (2007-10-10 16:32:38)

I have created the gallery 'A Scratch Challenge'
http://scratch.mit.edu/galleries/view/6574
the first challenge is to make a sailing game/simulation.
the complexity can vary (i tried to make a very realistic one but it was too hard for me, hope someone else does better) so i hope all levels of scratchers can try.
GoodLuck to all who try.

Last edited by bigB (2007-10-18 15:52:17)

archmage wrote:

Hey here's a small challenge that will test your problem solving skills.

Create a program that will generate a random number between 10 and 100 and if the number generated is a multiple of 5 make a sprite say "Beep" if the number is a multiple of 3 make the sprite say "Boop" and if the number is a multiple of both 3 and 5 make the sprite say "Bop".

Oooh, sounds fun and easy. Can I make an entry?

or not. 

Hey Archmage I did your challenge...

http://scratch.mit.edu/projects/relyt12101/56591

What do you think?

i have decided to use this idea.
the new challenge is to create a game that is based on pacman but to add your own touch to it.  maybe it could be two player, have extra bonuses or a new theme.
this is the gallery
http://scratch.mit.edu/galleries/view/6574