First of all, creating an large world game as a solo developer for a game jam is hugely ambitious and impressive in itself. 

The overall look and feel of the world you've created shows promise.
The visuals and environment design demonstrate your skills and have potential for further development. 

However, there are certainly areas for improvement, especially in tying all the elements together into a cohesive gameplay experience:

I was often unsure of what I was supposed to be doing as a player or what the goals and objectives were meant to be. Some more direction and tutorials would help with onboarding new players.

The controls and mechanics could use more polish - I found myself falling off the map in certain areas as I tried to explore. Smoother controls and collision detection would enhance the experience.

Expanding and connecting the gameplay loops and different mechanics you want players to engage with will help tie the world together. Right now, it feels more like an environment to explore without clear purpose. Defining the core gameplay will make exploration more meaningful.

Overall, you've done fantastic work in building the foundation and showcasing your technical skills in this  solo project. With more time to refine the mechanics, add gameplay loops, and polish the player experience, you'll have something special on your hands. Keep up the creativity and effort!

I didn't understand what I need to do and what is my final goal. But I can say that environment was done very well but requires to be more polished. I think you have a good idea to continue work on!

Tying everything together in an open world game for a solo dev was always going to be tough, so what you've accomplished is certainly worthy of recognition. I tried exploring the world, to appreciate the scenery you built, and yeah, managed to leap off the edge haha. But yeah, certainly much that needed doing. I could tell the concept you're going for, and with the right time, and polish this will turn out to be great stuff.