Nicalis did not port the Nintendo Switch version's added content and features back to the PC version, even when they re-released the game for Epic Games Store and GOG.
According to this comparison, the PC version is missing the following Nintendo Switch-only features:
- Widescreen (PC version is 4:3-only and Nintendo Switch version is 16:9 only, a feature should be added to dynamically adjust the aspect ratio)
- Local Co-Op Multiplayer
- Dynamic lighting and animated talksprites
- Stereoscopic 3D from the 3DS eShop version (can easily be implemented to the game to enhance the game for VR headsets even if the game would still not be true VR)
- Famitracks soundtrack
- Ridiculon soundtrack
- Sand Pit Challenge

We should complain to Nicalis to bring the Nintendo Switch and 3DS enhancements to the PC version.

I will not be buying the game on GOG unless it is free since I already got the game for free on Epic Games Store and Tim Sweeney bought it for me with his sweet free giveaways.

Oh! I didn't even know I had these updates.

In my case I already bought it, even though I also had it at Epic Games, but it was more for the achievements.

The game had been on my Steam wishlist since 2017, ha, ha... and never got the discount that was now on GOG.

I bought it again here as it is a pleasure to have this game in my GOG library (the achievements will make me replay too) but I would like to add another element to your list.

Even today, Nintendo 3DS has an exclusive version of Cave Story with 3D graphics. Luckily I have a physical copy and I've been able to enjoy it several times, but it's pretty absurd that Nicalis hasn't ported this version to other platforms yet, which by the way turned 10 last month.

Unfortunately, Cave Story has different enhancements and extras divided into its versions on Nintendo consoles. Possibly some kind of strategy to always justify a new purchase of the game.

The physical 3DS release is a full remake and not the original game. And it was made by NIS America and not Nicalis.
Nicalis should, however, add the stereoscopic 3D support from the 3DS eShop version as a VR mode for Switch and PC.
The stereoscopic 3D in the 3DS eShop version has a diorama/pop-up book look to the 3D and this would look great in VR.

Yeah, where the widescreen at? Very strange to release it this way.

The GOG version of CS+ is slightly different than all versions of Cave Story+ PC thus far. Instead of using SDL, it is based off of nicalis's engine framework(?) "KAGE", which was also used in the switch release of Cave Story+. Currently, the code is the same as the wiiware/steam versions, but I can see them having an easier time porting the switch content to PC, now that it's based on the same framework. That's of course, my theory, at least. You can tell it's a new engine solely from the fact that the game now uses .png files instead of .bmp, the pixtone files are now .wav files in the data/base/pixtone (?) folder, and some other minor changes I can't remember probably.

This is still the PC version at heart, of course, but I'm not going to lose faith in nicalis on this.