Yes, it is possible. But if you want to explore her ending, you need to let her rim you (you can skip the part where she fucks the MC).
The Steam version has Steam achievements. Other games with Steam achievements also have an in-game screen where you can see achievements you have earned even in the non-steam version, but this is not the case.
Some of those achievements point you to some hidden scenes that you probably won't unlock on a regular play of the story, similar to some bonus content and extra gallery unlocks. All that content is available on the F95 version, but without achievement unlock.
EDIT: I have bought the Steam version (to support the devs), and comparing that version with the one here, it seems it has more changes than just achievements.
In weeks 1 and 2, many scenes have animations instead of static images, so its an improvement. Week 3 also has the walk-through DLC not available here yet.
Also, in both weeks, the story is censored without the blackmail component being changed to a one million dollar price. In F95, only week 3 has the censored mode. Anyway, I don't find this one a good change, and I still use the uncensored patch, but if you want to play with that mode in Steam, you could do it on all weeks.