While you need better Gameplay mostly it's not effective to have a sketchy - even glitchy graphics, if you could have the best of both, that'd be great!
Graphics, I don't find the gameplay very important. A game can have an excellent gameplay and can be neither impressive nor pleasing, but a game with amazing graphics is always impressive and captivating.
gameplay is definatly better than graphics. i would rather play a fun game with pixel people as the charectars then have a dumb game with good graphics