Can you please verify that you did the following two things? (as described here)
"To run the example, you need to:
- Add a layer called "StaticEnvironment"
- Enable "Auto Sync Transforms" in Physics2D settings"
I cannot do these two things automatically from inside the asset so they must be done manually by people who want to run the Dead Cells example. If I remember correctly, the colliders didn't work for my until I enabled "Auto Sync Transforms".
It's correct that there are both composite colliders and platform effectors. Platform effectors are only enabled for the "Platforms" tilemap layer so that the player can jump through platforms but no through walls.
Please do the two steps above and let me know if it works. I tried the Dead Cells example on my computer and it did work properly.