I wasn't put off my the marketing until I saw the film, and how long it took to get to the big reveal (plus all the misdirection along the way, which is now rendered pointless for having seen the trailer).

I had issues with From Dusk Till Dawn, but I didn't mind the idea of the genre switch. At the same time, it is an entertaining watch. Personally, I prefer genre switch films to do so more gradually, like a slow burn. Example: Angel Heart, which begins as PI noir thriller and winds up in full-blown Faustian Grand Guignol horror territory.