Unfortunately many games launch with enticing videos assuming
that a cool soundtrack , cool visuals and a story is all it takes.
But i think games are not videoclips.
Only by playing you can understand if you like a game.

Isnt it strange to must buy a game and ask a refund?

Agreed games are not video clips.

However most games seem to be cash grabs, crap controls or other. As such never buy a game at full price (Or god forbid, preorder) without checking a few reviews which will cover 80% whether you'd be interested in the game still.

You don't need demos, but demos could be a plus.

Sadly they are right , all those sell games better and for cheaper than demos.

+1. Nothing beats playing the game by myself :)