Update Rive Game project

Update this rive project to work with latest Rive features and latest defold Rive extension. Create a fully fleshed out small working game.

## Some Tasks Ideas:

- Update Rive project to use latest extension and Rive render.
- Add main menu / title
- Add UI for Health / ammo / score etc...
- Add pickups for ammo , health
- add more enemies / small events
- splattering effects when destroying enemies
- create environment objects
- death mechanics
- high score
- data save for keeping score
- BONUS achievements

The issue names no files, tests, or entry points; start by inspecting the sample project and its current Defold Rive integration, then compare it with the latest extension and Rive features. Clarify which listed game elements are required, and consider the work done only when the agreed scope produces a complete working game.

Written by the indexing model from the issue text.