A second crowdfunding campaign has been launched for nostalgia-baiting side-scroller Mighty No. 9.

The PayPal campaign is being run with the aim of adding bonus content to the game, according to designer Keiji Inafune.

There's only one goal announced so far: full English voice acting will be implemented if US$100,000 is raised.

Mighty No. 9 studio Comcept has been quick to emphasise that the game it proposed in last year’s Kickstarter campaign will be completed regardless of the outcome of this second funding round.

“Any new funding will NOT go towards existing content in the current state of the game, but bonus content to be implemented into the title,” an update on the game's official site reads.

Last October, Mega Man successor Mighty No. 9 was funded to the tune of US$4m across Kickstarter and PayPal.

It is expected to release on Windows PC, Mac, Linux, PS Vita, Nintendo 3DS, Xbox 360, Xbox One, PlayStation 3, and PlayStation 4 in autumn 2015.

Pre-orders for the game are now open, with a digital copy of the game costing US$23 (NZ$26). There are also Collector’s Editions available for US$50 and US$80.

Meanwhile, a Mighty No. 9 animated series has been announced, for which production company Digital Frontier is seeking funding.