Mighty No. 9, an in-development side-scroller from Mega Man co-creator Keiji Inafune, has raised more than US$4m from the public.

The game brought in US$3,845,170 and US$186,380 from Kickstarter and PayPal repectively, making it one of the most successful crowdfunded games yet.

Inafune was only seeking US$900,000 for the project, so the extra money will go into a making-of documentary, chiptunes soundtrack, extra stages, and new game modes including boss rush, turbo, new game plus, and co-op challenge variants.

The extra funding will also allow the game to be released on Mac, Linux, PS Vita, Nintendo 3DS, Xbox 360, PlayStation 3, Xbox One, and PlayStation 4 as well as Windows PC.

Mighty No. 9 developer Comcept features the level designer from the original Mega Man, the composers from the first two games, and others that have worked on the series.

The game is expected in autumn 2015.