Thanks for playing!
The connection between both parts of the gameplay is explained in the dialogue and in the instructions below the game on the game page. Hitting targets adds to the value of the card you're dealt when you choose to hit. So hitting 3 goblins and a pink wall in a throw gets you 3 + 1 = 4 as a card, for example.
Thanks for the feedback, I think the game would've benefited from making this connection more obvious without dialogue. Something like a combination of numbers popping out of targets and a running count of the current throw's points would've helped here.
This is a good example of one of those things that are harder to see if you've been the one working on it.