I think I have the GOG version... or is it the steam version? can't remember, but, I had a very hard time at the firecracker part too. It wasn't slow enough and I died every few seconds. But, it was do-able. I would just go as fast as I could to the left, and each time I died, I would put do again, and keep going, and after about 100 times, or about 20 minutes, I finally made it to the crypt and I could keep going. so, just be patient and you can do it. It will just take longer.