Quick update 1-23

Because I am still on a travel, I don't have much time to test. If there are any issues, please leave some feedback in the community, thank you!
1 If the building camera cannot be moved (this happens on none 16:9 screens), Use WASD to move the camera
2 Now we can adjust the difficulty levels in the ESC main menu (note that such modifications may damage the integrity of game data, so do not abuse them excessively)
3 The original difficulty option of "enemy HP" has been changed to "combat difficulty", which affects multiple factors. For example, in simple difficulty, monsters that knock down players will not force player into combat mode and slow him down
4 Modified the hit boxes of the auto-farms, now it is more consistent during construction
5 Some high-speed monsters are now slightly slower, such as eagles
6 The mill can grind flour a bit faster now
7 Minor fixed some game text,
8 When trees fall, players will stop cutting
9 Nightmare bosses will not spawn in early stage now