Decided to try out the game but there seems to be a game breaking bug. I am currently in stage 7 or the cave level and each time I go in the portal to exit the stage, it gives me the game over prompt. Sometimes it lets me in the portal which takes me to a cinematic then once the character enters the second portal, it gives me the game over prompt.

Is it because I am using cheats? I tried the first level with cheats enabled but I was able to finish it without encountering the same problem.

Which episode are you talking about? I just finished episode 1 and I had no problem at all.
I did not use any cheats.