I can downplay something.
Can I thus "upplay" a thing or not? What do you think?
I can downplay something.
Can I thus "upplay" a thing or not? What do you think?
No, unfortunately 'upplay' is not a word. If you want to say the opposite of 'downplay' you can always use words like: magnify, overstate, exaggerate, amplify.
However you can say "play up" to mean: to emphasize something.
You wouldn't "up-play", but you could overplay something.
talk up provides an antonym to downplay - it matches the informal/colloquial usage.
He talked up his work experience to secure the position.