Am I misremembering or could you play games on Teletext? I feel like I remember playing very primitive and janky videogames on the TV as a child in the 90s, but I might be making that up.
My clearest memory of Teletext is how slooooow and unreliable it was to load anything. But I sat it out and waited. Compare that to now where if your website takes an extra second to load then you can lose like half your traffic. Everybody was much more patient with technology back then.
They had bingo games running on Teletext in Denmark.
There were also interactive pages where you could phone in and press numbers to access a much larger set of information. You'd get your own temporary page number (that anyone could technically see), and the teletext broadcast equipment would insert your updated page into the stream when you pressed a number.
There were definitely puzzles, quizzes, and jokes. You could reveal the answers by pressing the "Reveal" button on your TV remote. I don't remember games per se.
You would dial a premium rate number and you would then be read out a page number. You went to that page and used your telephone keypad to do interactive stuff and the page would update in near real time. The two biggest things were managing your Sky fantasy football team and banking from the Co-operative bank.
Our TV had a function to let you see all active page numbers so I would often go and spy on what other people were doing.
There were occasionally multiple-choice adventures using the colour buttons. I must say as much as the slowness is annoying in hindsight, I still have memories of how exciting it was waiting for your team's football score to page back into view, and the thrill of seeing your team had scored.
I remember channel 4 had "bamboozle" - a basic janky quiz game - on their Teletext service, it was a daily adventure between friends to solve each day.
My clearest memory of Teletext is how slooooow and unreliable it was to load anything. But I sat it out and waited. Compare that to now where if your website takes an extra second to load then you can lose like half your traffic. Everybody was much more patient with technology back then.