you can. Just go into the saves folder inside the game. C:\Users\(username)\Downloads\SabrinaTheHungryWitch_0.2.9_WIN\SabrinaTheHungryWitch_0.2.8_WIN\save
thats the directory in you computer that'll take you to the saves. Replace (username) with whatever the user for your computer is. I personally don't have 2.9, but you should be able to find it easily if that directory is wrong. From there just copy the files from the folder of the same name in 2.8 to the 2.9 folder and everything should transfer. worked fine for me btw, so it does work.