I think that your proposed modifications seem to be headed in the right direction! I do have a few questions:
- What are you planning on doing with the levels? Adding new ones, or modifying existing ones? Either way, be sure to differentiate them through new and unique obstacles, challenges, etc.
- When you say an 'element', what does that mean?
- What types of abilities or items are you thinking of adding? Will this involve scripting, or modifying existing code?
I'm looking forward to seeing your final product!