Custom enemies will be expanded from Mari0: SE into a more powerful Actor system.The editor has received several substantial improvements over the first game, with new tools including selection (rectangle and magic wand), copy and paste, fill bucket, zooming/resizing the window, multiple tilesets, stamps (groups of tiles), layers, and more.Portals can even rotate freely, although this may not be used at release. Portals have been entirely re-written and are no longer bound to tiles they can be placed anywhere, including slopes.Tiles can now have slopes and other free-form polygons for their collision data.The following is a list of things shown or mentioned by Maurice while the game was being developed, and may not reflect the future of the project.

Progress updates continued into 2018, working on the game's editor and game engine. On December 22nd, 2017, Maurice stated that he removed all 3DS-related code, since Love Potion was not yet feature-rich enough to support it. The next day, Maurice streamed 'Secret Mari0 2 development', attempting to code pixel-based physics into the game. He commented that he should just make the rewrite based off SMB3 instead at that point, and later requested sprites of Mario with a portal gun in the SMB3 style. On October 4th, 2017, Maurice reworked portals with the ability to be sloped. Since then, he has posted regular updates on the Discord server. In September 2017, Maurice started rewriting some of Mari0's 5-year-old code to be more optimized, and to run on 3DS. Although Turtle had previously attempted a 3DS port, it was was unsuccessful. Mari0 2 began as a project to port the game for TurtleP's Love Potion, which is a port of Löve to 3DS homebrew. It's a rewrite I started and then I made it not bad so now it supports angled portals in arbitrary positions, runs better, and other stuff.

Mari0 portal download