Finally I added a timer with Kdenlive (that is working on Linux ^^') and I'll post my run when the render finishes.

But I always have like 229 / 230 on 1st level, so game is not faster at all x)

I have a problem with my actual speedrun. I don't know how to put a chronometer / timer on my speedrun video, and I think this would be a problem when verifying if my run is okay. Other information, I'm on Linux (Ubuntu 16.04), and my PC can't afford editing softwares. Thanks for your future replies.

I don't understand how can the game be faster, and how can we see it. It's quite a big problem on Happyland Adventures speedruns.