The sprite viewer exists, but having a gallery for CGs is not viable in the early state of this game, as it'd require an astronomical amount of work to recreate the modular variants of the CGs, and then those options would have to presented to the user in a way that doesn't obstruct the CGs, would allow scrolling the CG (many are larger than the game window), and work on touchscreen devices... and then I might have to go back and redo everything if too many engine changes occur. The non-placeholder CGs (with the exceptions of the Keisuke shower sex and Britney measuring ones, as they need reworking) can be accessed from a Dropbox folder online in the "Extras" tab on the main menu, but here it is as a hyperlink.
My advice for now is that if you want more, save the game at certain points, or press the S key to take lossless screenshots of the game window (you can press H to hide text).
I don't upload it as a ZIP. itch.io does that on its end as I use Gradle to upload the folders of the loose files.
I have to upload multiple files together, i.e., for stuff like the SFX sources as a clearly-labeled file due to creative commons attribution license or else I cannot use many SFX I have, the changelog (a lot of websites scrape uploads without linking to the changelog), and the flowchart.