How do I Design pixel art for different resolution

I'd like to make a pixel art looking game, but i want the pixels to look really big, kinda like the game Tiny Tower.

Screenshot here:

lh3.ggpht.com/ennz0LbWEim0UilZ-gkOSQOm5AX8ai2owHM2E9L76mXmuQxdlQU_1q8S0jjesw9pwk8=w705

I'd really like to be able to see the pixels even on a high resolution display like a retina display ipad.

Is it best to create it in high resolution and each pixel will simply be a block of 8 pixels or something?

Or would it be best to do all of the art at 320x200 and let the device scale it up really big?

thanks.

First of all , Turn Sampling to Point and then do not let your device scale the images ( For a static image , Just make the Width and Height egal the the screen size )

Construct 2 has a nice option called "Sampling" in the project settings. As Whiteclaws suggested, turning it to "Point" will allow that nice retro pixel look.

When creating the images, don't do a manual upscale (8 pixels for each "pixel block"). Instead, just create each image at 1:1 scale. Trying to do high res images of low res images is a waste of time and resources, both in production and game performance. Only do what you need to in order to reach the result you want.

Construct 2 has some nice options available in it to upscale the screen for you. Under the project settings there is an option called "Fullscreen In Browser" which allows you to set up scaling. These options will automatically upscale the game to the browser's window size (or screen size when the browser/Awesomium is in fullscreen mode).