ruined? no.
will it look as you imagined and will the seams match up? likely not. However, if the error is consistent amongst all blocks, it may work out okay without too much notice.
That being said, you could move forward with it as is and still have a functional quilt in the end, or you could turn them into something else where the error is less noticeable (rail fence?) and start over with a new top using your newly learned lesson.