From the readme file:

This is a demo for Petals of Rose

Demo contains:
- Branching story (total of 20 possible combinations)
- 11 Hentai scenes (7 unique CGs).
- Complete first story event, side events and masturbation events.
- Recollection room / Route viewer in the same room.
- 5 types of clothes / 4 types of underwear
- Somewhere around 2+ hours of gameplay.
- Night/Day system (not clock based, because fuck that, it's annoying).
- Hand drawn CGs (cringy art, woo!)
- Prologue of the story.

Since it's a demo and not full release, some changes were made.

----------------------- Changes for demo -----------------------
- For waitress event, if player doesn't have enough ero stats, with game tips on, those can be changed to view the next scene.
----------------------- Additional information -----------------------

- For some options: Open Menu and go to Key Items. You can turn ON/OFF weapon image in dialogues and/or Game Tips.
You can also go to Recollection Room from there.

- Choices, fucking choices, man!
Main story branches, then each branch branches again, because I heard you like branching stories.
If you decide to replay it and do different things or discover new stuff, you will be able to tell how much the story can change in the end.
Also, in Recollection Room you can view progress of your route and after completing story event - check a little summary regarding that route.

- Hentai events care about your stats!
That's right, ero stats will affect how hentai event goes, on it's scenes, dialogues and such.
Especially side events that aren't needed to complete the story.
Story events are different as in some cases, player simply can't get enough stats to impact them.

- Clothes!!!
Wear whatever you want, as long as ero stats let you wear those skimpy outfits!

- Exhibitionism? Shame?
Yup, why have one stat when you can have two?! Also, they impact different things when it comes to events/items.

- Karma? What this stat does?
It does something... you won't be able to check it, so why bother?

- Events are divided into three types: Story, Side and Mini.
- Story: Important events related to the story, required to progress further. (1 in demo)
- Side: Not important to the story, mostly for extra hentai scenes. (1 in demo)
- Mini: Small events for flavor, for few extra scenes or anything else I come up with. (3 in demo)