SOLUTIONS IN-GAME AND LEVEL 8 CHANGES: If you get stuck somewhere you can press 'Q' or click on the key button at the top left of the screen. It's an in-game walkthrough of the level. You can close it in the same way. Also the water statue from level 8 was removed.
I missed the mark with difficulty that requires too precise movements, so I made the following changes. Replaced a trick jump that was required in level 14 with something else, as well changed the hint appropriately. Increased the time window required in level 13. Decreased the difficulty of level 15 a bit. Increased the delay between projectiles by a small amount.
Thank you to everyone for reporting the bug in level 5 that appears in some browser/OS combos and sorry for the inconvenience ! I fixed level 5 and also added some changes to some other tight jumps. Also changed some names to better hint at the trick of the level, added the fact that non-cursed cats are ignored by Nyahotep in the instructions of level 3 and made level 14 easier. Please let me know if another problem occurs.