After reading your thoughts on GameJamming in the Discussion section, and then reading between the lines, i devised that you are dedicated to improving your game development skills. Here are some constructive points i observed while playing your game.
Mechanics:
Why do i move 50% faster while moving diagonally?
- There is a simple way to normalize movement-speed for all directions in Unity:
https://forum.unity.com/threads/how-do-i-used-normalized-my-diagonal-movement.30...
There should be some similar method for Java: https://gamedev.stackexchange.com/questions/144566/how-can-i-make-diagonal-movem...
Why is there no mini-map?
- This world is huge, and very similarly decorated, so it would have helped greatly.
Why do i die when i walk out into the red area in the south-east, but when i try walking into it in the north-west, it didn't kill me?
- A better alternative, according to me, would have been to add screen bounds there instead.
Graphics:
Why can i walk over the river?
- Colliders for water, and adding a bridge?
Why is there a tree in the river/on the houses?
- If you auto-place environment details, why not make the placing conditional?
What is the pitch black ground supposed to represent?
- Desert , rock or swamp would have been preffered.
Why can't i pass behind the crown of a tree, even though it should be on a higher elevation then the player?
- Making the tree-sprite from 2 different sprites, where the trunk is a collider, and the crown is on a sprite layer above the player might have helped.
Why are there anti-aliasing effects on some graphics, like they've been greatly up-scaled?
- You could have painted all the sprites to scale instead.
Tips:
I would definetly recommend you start to learn Unity, if you want to make better games. Can be a daunting learning curve in the beginning. But Unity brings a thousandfold of tools that solve many common game-dev problems such as: Tile-mapping, Prefabs, Animator, Terrain-editing and collider and physics, and countless others. Don't learn all the tools for the sake of learning. Do a project, and learn each tool in the course of development. Like building a map with Tilemap Editor. Animating your characters with the animator, etc.
When painting sprites, adding 1 more darker color to each region of color (tree, rock, sword, enemy body) really helps to bring depth to the sprite. Shading is not especially difficult. Imagine the light being an eye, looking at the model from one direction (in a 3D space). What the eye cannot see should be shaded (painted in a darker tone).