Hello there! To be honest, looks like you're at the very beginning of UE learning. It is nothing wrong with it, we all are learning and become better. But with a current lack of experience, you have issues in your game. I can point some of these now:
1) The creature keeps moving infinitely when [Game Over] screen pops up. Not aware of your setup, but try to call "Stop Moving Immediately" and disable the movement input response.
2) Progress Bars are still decreasing over time during [Game Over], probably you have it called repeatedly over Event Tick. Just disable this countdown - a branch with a simple boolean like "shouldCountdown" would help.
3) And after [Retry] is pressed, i was unable to control the creature. Most certainly the newly spawned Character is not being Possessed.
Here we go! But don't be fret please. All issues could be fixed. Keep up the great work, and let's play a more updated and improved version on the next jam! Thank you!