My most recent: Language without math, Brainiac, alpha 0.0.9 on 10-20-2018 as date. https://itch.io/post/574719
Awhile back: Language with math, difficulty not stated, alpha 0.0.7c on 8-23-2018 as date. https://itch.io/post/514492 Went through comment section to find this.
Also, put zombieskull leaderboard for accessing TV game first. Don't think there are anymore secrets...