Questions in Game Dev

who can advise to me a free and good (NOT UNITY) game engine?
I want to make a FNAF Fan Game (I don't know if this should be posted here), but I am trying to figure out how to make the assets like office, camera's, phone guy, etc. Is there anything that I can use?
When you play 2D platformers, do you prefer to have your momentum carried in the air, or do you prefer having full control while airborne? (asking for a project)

Hello! I want to remake the icon of my game, any ideas of how I could improve the current one?
Revenot is a roguelike and aRPG mix, the maps are created randomly, the icon represents part of the story, which is in a forest, but I want something broader.
This has been on my mind lately, since I haven't delved into making more complex characters.
In games in general, what do you like to see in a protagonist? What would make one really interesting to you? This can include traits, strengths and flaws.