Hi,
We're very happy that you like the game so far and thankful for your kind words!
To address your questions:
- there are no endings yet, dev has plans for multiple endings, one of them Yuna being pregnant... As of now, nothing really happens when you choose not to rewind, just a "thank you for playing" screen, so it's advisable to rewind in order to continue playing;
- there will be more characters that you will be able to have sex with - that's for sure (dev has plans to add psycho girl after kaede for night fun), but I'm not sure if there will be any romantic relationship with other girls besides Yuna
- we're aware of the occuring problems in Android build, the main issue is that dev mainly develops the game for PC platform, he will invest some of his time to tweak the Android build to be working almost flawlessly as is the PC version, but it's a little lower on his priority list, probably he'll get the story and interactions first and then do anything performance related. As for the scroll bar, it is in fact possible to move it around using touchscreen, but you'd have to tap the exact few pixels which isn't an easy task, regardless, translation has been halted until the game is nearly finished, so it's veeery incomplete
The game will definitely get more updates, feel free to join our discord server to be up to date with the development in form of daily devlogs, ability to vote in various polls, request a feature and be a part of still growing and helpful community!
Cheers