>>713508893
Bit extreme since sometimes announcing games is done to get investors' attention or new employees or even a publisher. However I do agree with the notion that by that time at least a vertical slice should be demonstrated in like a 10 or so minutes gameplay trailer.
Announcing a game with a cutscene but then waiting for months or even a year to "reveal" the gameplay, especially if you're already a big dev like Snoy's first party or Microsoft should be mocked. These 2 being the latest notorious examples.