Factsheet

Basic information, platforms

It's Mari0 (with a zero)
Yes, this is an actual game being developed - it is not a mod of any existing one and is not based on the original game code. It's coded using Löve framework (info at the bottom of the left menu)
The game will be released 100% free
All the source code of the game will be available after release
The game will be released on Windows, OSX and Linux based systems.

The game will have mappacks, which will be downloadable from ingame. Users most likely won't be able to publish maps directly, but will be able to send them in and we'll add them for everyone to use
Per mappack custom tilesets will be allowed
The primary maps will have a story and some portaly puzzles
Level editor will be embedded in the game so you can edit the level while you play
Original SMB levels and Lost levels will be included
Primary player will use mouse and keyboard (or gamepad), other players gamepads
Simultaneous multiplayer up to any amount of players, only limited by the amount of joypads you can connect to your computer - splitscreen for 2 players will also be included
Online multiplayer is experimental at this point and won't necessarily be included in the initial release