BTD6 No Encrypted Secret 35.0

Proof that the secret was a recent addition. Aside from my testing confirming this is not in 35.0, Minecool tested other versions and confirmed that the secret was in fact added with 42.0.
For those wondering what the secret actually is in 42.0 and above, I recommend watching this video, or the many others around the internet:
• BTD6 'Encrypted' Easte...