1. At first, go to the game folder. By default : C:/Program Files(x86)/Naball Evolution Invasion/
2. Next, go to subfolder 'System' : Assets/scripts/System
3. With Notepad ++ or an other text editor, open RAMDictInit.py
4. At the 9th line, change
l.globalDict['chFly'] = 0
l.globalDict['chFly'] = 1
5. Now, you can start the game and the jump key is converted by the flight disabled key.