A good new Worms game needs six things:
1. 2D
2. Highly predictable gameplay physics, with a good sense of weight and friction, but also easy to launch objects.
3. A super-simple, super-fast Ninja Rope. Should feel more like a pole than a piece of wet spaghetti.
4. A CLEAN art style. You should NEVER have to guess what you're looking at.
5. LAUNCHES with key features WA players take for granted (fully functional chat, custom maps, lots of scheme settings).
6. Zero dead air - if the player has to wait for even a fraction of a second, it better be for a damn good reason.
Formulas make people comfortable. They sell. Don't reinvent the wheel, just upgrade.