Sentence:  The <WSD>"debug mode</WSD>" enables full flight around every level, plus you can add a whole mess of objects to the stage at the press of a button. 
Meaning of the word marked with <WSD> tags:  A (usually hidden) tool or set of tools in a video game used in its development and testing, the use of which typically enables players to cheat, modify the game's behaviour, or perform diagnostics.