Re-adding all the eroge elements from the original to the new game wouldn't be as simply as dropping some PNGs inside a graphics asset pack and calling it a day. Most of the functionality for how these graphics were presented in the game were never coded into the new re-release in the first place. If you wanna know what I mean, please read further:

Game Structure

The game is divided in sets of levels (which I will refer to as "chapters" from here on out). With four levels a chapter, there's one image shown at the end of every level. There's also a flashing, auto-scrolling silhouette version of the artwork shown before the chapter starts, and then a player-controlled scrollable version of the artwork at the end of the chapter.

This scrollable artwork can be clothed, half-naked, or nude, depending on machine settings and how many "H tokens" the player picked up in that chapter. The "H tokens" — the "H" maybe coming from "hentai", probably meaning "helicopter" in the new version — are spawned directly after the player blows up the first computer in any level, with a total of four tokens to pick per chapter.

Here's a table indicating what the player will see at the end of every chapter:

Now, let's see how much of this remains in the final version, starting with…

The Flashing Silhouettes

These were simply not implemented in the game, as they didn't fit in with the re-release's theming. In the original, these would scroll over the woman's body, to entice the player to keep playing, while also flashing.

Neither the flashing nor the scrolling are coded in, so this can't be implemented without rewriting the game.

End-of-level Slices

In the original game, these 320×224 slices are taken from the fully-clothed versions of the artwork, the first level generally showing the feet, and then progressing all the way up to the face by the fourth level.

In the re-release, these are instead stored as a single 320×224 background, with additional transparent layers (generally showcasing artwork of the player and the chapter's enemies) appended after, which are then combined visually in-game runtime. The first level will show the background first, with black silhouettes of all the other visual elements being revealed as the player finishes every level, the fourth one after completion showing the full version.

In theory, this could mean a modder could maybe shrink down some (but not all, read below) of the pictures to fit a 320×224 resolution, and store the "nude parts" as elements that are revealed level by level. In any case, since this is not how these are implemented in the original game, this task would require wholly original assets, and would fall way beyond the idea of preservation.

This, without even considering the fact that at least two women featured in the game are presented as vertical images, with only the four lasts ones being anywhere close to horizontal enough to fit without leaving huge amounts of blank space around them, and that's after downscaling to resolution!

End-of-chapter Reveal

These were entirely removed. In the new game, there's now a cute bonus stage in which you jump off an helicopter and pick-up coins on your way down. A modder would have to rewrite the game to add the reveal, before or after the bonus game.

The Ending

The original game (spoilers?) ended with a slideshow of all the girls, and finally a small portrait of all the girls posing together (also included in this pack). The idea of the slideshow remains in the game, although it uses the aforementioned layering system for animation.

The group photo, which in the re-release shows all the game's enemies and the players, would be the one element that could easily be replaced by just changing the graphic to the girl group photo in the original.

Miscellaneous Stuff

There are other changes in the game which wouldn't be trivial to implement, such as:

• They removed all the nude and crass animation frames from the rally show floor girls. The animation routines may not even be implemented for some of these. (Not included in this pack)
• They removed all but the first background transition tiles from the game, which featured "not Jessica Rabbit" and other small icons showing things like drinks, and a woman's bodysuit. (Not included in this pack, but can be seen here.)
• (Spoilers!) One stage boss being moved to the very end of the game.
• Probably other smaller changes which I didn't see while finishing both games back-to-back in such a short time window.

Conclusion

Even though the tools for editing the game's graphics are available, the amount of coding that would be needed to actually make the re-release behave like the original game would be tremendous, if not impossible without the game's source code.

If anyone wants to try it themselves, I give you my blessing and wish you good luck. Don't forget to leave a link in the comments here, and sharing it with the other players on Steam. Wew, that's a lot of words. But this is the end. Cheers!