Cave Story

Update: Ema – who worked on a fork of the CSE2 version of Cave Story – has gotten in touch to clarify some points:

1. This DMCA is strictly for CSE2, the fanmade decompilation of the original freeware version of Cave Story. Said freeware version is unaffected by the takedown, and can be downloaded at as always.

2. To the best of our knowledge, Nicalis in fact owns the Cave Story IP. We have no reason to believe that this DMCA takedown is illegitimate in any way. While there can be fair use exceptions for decompilations like CSE2, the burden of proof rests on the project, not on the copyright holder.

3. Nicalis has a history of being very supportive to the modding community. At this point, we don't suspect any ill will. We are approaching Nicalis in an attempt to clear up this misunderstanding.

4. The maintainers of CSE2 have no intention of disparaging Nicalis. It's by their good will that the modding community continues to thrive above ground. We unilaterally endorse the official commercial versions of Cave Story.

Original Story [Thu 26th Nov, 2020 09:30 GMT]: Publisher Nicalis is issuing DMCA takedown requests against sites which offer the freeware version of the iconic indie Metroidvania Cave Story, it has been claimed.

Created by Japanese developer Daisuke "Pixel" Amaya over a period of five years, Cave Story was released on PC in 2004 and quickly became famous with fans of indie titles. Nicalis came on board in 2010 to port the game to WiiWare and DSiWare, and also produced the enhanced Cave Story 3D on 3DS in 2011. Cave Story+ – based on an updated version released on Steam – was converted to the Switch in 2017.

Despite all of the various retail versions available, the original computer version of Cave Story has remained a freeware product and can be freely distributed online, and a mod community has grown up around the game.

Twitter user Buttons Montgomery posted the following message (warning: bad language) on November 24th, along with a screenshot showing evidence of a DMCA takedown notice:

So @nicalis has decided to start DMCA'ing the freeware versions of Cave Story and fan made rebuilds of the freeware version that supported mods while also largely not even using the original source code.

Remember: F**k Nicalis. Do not support Nicalis. Do not buy Nicalis games.

The tweet was spotted and reshared by famed indie developer Rami Ismail (he of Vlambeer fame, the studio behind Ridiculous Fishing, Luftrausers, and Nuclear Throne), who then posted the following message:

Cave Story is one of the most important games every made and I will 100% recommend you do not buy it. Download the freeware original, then buy Kero Blaster to support the actual developer of the game, instead of these ugly shenanigans.

One of the developers behind a CSE2 fork – which is a "decompilation" of Cave Story which has "an emphasis on accuracy to the original code" – has also responded to the original tweet, shedding a little more light on why the takedown request was filed:

I'm the main dev behind a major CSE2 fork, so I'd like to clear some stuff here!

Effectively, CSE2 was a decompilation project of the original Freeware release of CS. It appears Nicalis acquired the code of it when they got the IP. The DMCA was filled because of that.

The DMCA claims Nicalis owns the code to CS+ and believes said code exists in the repos, but that's not the case to our knowledge.

Several major participants in the CSE2 project (myself included) are currently planning to approach nicalis to settle on the matter.

It's worth noting that Cave Story remains available for download on sites such as, although, on November 24th, that particular site was updated with the following message:

Removed links to the CSE2 repo due to the DMCA takedown. A note about the CSE2 DMCA takedown was added on both the "download" and "custom engine" pages.

According to the Cave Story Community Encyclopedia, Cave Story is licensed to Nicalis but is owned by Amaya; therefore, it would appear that Nicalis is overstepping the terms of its licensing agreement by trying to snub out freeware versions of the game – although there are have been rumours that Nicalis has "duped" Amaya out of the rights to the game (this video does a good job of covering and even disproving these reports). Whatever agreement Nicalis has with Amaya, it has allowed the company to put characters from Cave Story into other games its has published or developed, including the puzzle title Crystal Crisis and the fighting game Blade Strangers.

This isn't the first time that Nicalis has been accused of questionable behaviour. Last year, a report by Kotaku alleged that the company was ghosting potential business partners and Nicalis boss Tyrone Rodriguez was said to have used slurs and mistreated his staff.

We've approached Nicalis for comment and will update this story if and when we hear back.