Mouse is invisible.

Do you have any screen recording or other similar software running on your computer? Do you have any game overlays running (e.g. steam, discord, GeForce Experience, etc.)?

could you please turn the debug console on and post the log here? To do that you need to open the config.properties file (found in the game files under /steam/steramapps/common/RisingWorld) with a text editor and change the value "game_debug_console=false" to "true". Then open the game wait until the main menu appears and the cursor disappears, then wait 10 seconds and close the game. The newly created log can be found in the Logs folder in the game files (same path as indicated above)

PS: you can just press Alt+F4 to close the game without using the task manager

As @Minotorious mentioned, this is likely caused by a third party program or a driver issue. Do you run the game in fullscreen mode? In this case you can try to disable the fullscreen mode, adapt the resolution to your desktop resolution and check the "Undecorated" box (this provides an alternative fullscreen mode which works better in most cases).

If the cursor is still gone, you can try to switch back to the basic Windows cursor. To do that, open the "config.properties" file in the game directory and set "game_no_customcursor" to true, then save the file and run the game. Is the cursor still missing?