Here is documentation of the differences in versions

Remember that version 1.3.2+ has a subcategory so you can do on version 1.3.1 or higher as you wish

1.3.0

• This version does not have the Japanese version which makes this version unviable for speedruns
• Plays 3 glitches that could be noticed while playing, are not useful for speedruns

1.3.1

• This version has the Japanese version which means you will save 2 seconds per dialogue
• The game has a bug that you can do the K6 ending without cutting two plants in front of the girls
• The game has a skip on the stairs to the door which bypasses the tutorial saving 2,350 and on this version it is simpler

1.3.2

• This version fixes many of the game's bugs
• Skip tutorial on stairs still works on this version but is even more difficult than on 1.3.1
• The bug for K6 has been fixed which means that this version is slower in this category
• Loading times have been added
• for K7 entering the caretaker's room with the girls while preparing for the ritual does not start the dialogs after entering
• This version is not supported on MacOS due to a bug in the build.

1.3.3

• This version is not very different from 1.3.2 for speedruns
• The macOS build has been fixed for this version

1.4.0/1.4.1

• The game has more save slots which means that practice saves will not be a major problem for this game
• Unofficial translations are added directly to the game which means they are allowed and Chinese (Simplified) is faster than Japanese

1.5.0/1.5.1

• This version improves game loading.
• Version 1.5.1 fixes an issue with opening the menu in the location where Kat is trapped.
• In the location where Kat is trapped, waiting for the dialogue to appear takes 3 waits instead of 2, losing 7 seconds.