Create your own interpretation of the iconic first level of Super Mario Bros. You can reinterpret it however you like, but the resemblance must be clear. Also, it should go without saying, but, no rips or edits.

Canvas Size - Unrestricted.
Colours - Max 13.
Transparency - No.
Animation - No.

The following pixel artists produced Pixel Joint's top rated pixel art for April 2013. Many thanks go out to this month's top pixel artists and all the members who took time to rate.
 

Elk's Forest Of Desolation by Elk

Red Riding Hood by a3um

monsterz by Dorong

Sg. Helga The Axis by saiko-raito

Psychedelic Side of the Moon by MrBeast

Plataform Mockup by BlackFang

STAR WARS; Battle of Hoth by Reo

Doctor Angelicus by Tojo

This is ChibiSparta. by Orkimides

Sentry going up! by Nevercreature

Create a still life which includes a strong light source; for example, a candle.

Canvas Size - Max 200 (width) x 150 (height).
Colours - Max 24.
Transparency - No.
Animation - No.

Octopus Apocalypse is running a Kickstarter campaign to bring retro style pixel art to tabletop gaming. Pixel Dungeon is a series of print and play paper miniatures featuring the lovely pixel art or lovely pixel artist Zigmund Kawakami. Rewards include discounted miniatures and the opportunity to get custom miniatures ranging from a single mini to an entire product line.

Full details available on the Kickstarter page .

Just finished my pet project, a pixel-perfect game (256x256) about scrounging for supplies, blocking doors and mostly surviving as long as possible.

Play it in your browser (best on Chrome) here

Create an isometric spaceship - either as a part of a scene or as a standalone sprite.

Canvas Size - Unrestricted.
Colours - Max 25.
Transparency - Optional.
Animation - No.

Pixelaria, Brazil's most popular pixelart site gets revamped New interface, new team. All redesigned!

 http://www.kickstarter.com/projects/1445624543/anne?ref=home_popular

The pixelart looks pretty good, and the gameplay looks interesting. I'm not sure who the artist is or if we would know of them in this community, though.

PJer Jamato-sUn is hosting a gameboy mockup contest over at dA. All PJers are invited.

http://jamato-sun.deviantart.com/art/Spring-love-Gameboy-3000-points-pixel-contest-369057858
It has prizes too!

Depict a real-life animal living in an environment that it normally couldn't survive in, e.g. a dolphin in a desert.

Canvas Size - Max 150 x 150.
Colours - Max 16.
Transparency - No.
Animation - Optional.