The nonland side does vary, but, judging by the cards that have already been previewed, are overcosted spells
There are also ways to make a ton of Treasure tokens too that you can add to the deck
Then you tap three, one of which is Tangle Wire, so this ends up netting you a lot of tempo if it comes down before they can find permanents to tap other than lands, especially if you have one and two drops that you can tap
The combination of Amber and Amethyst creates a lot of potential for interesting deck designs, but if you want to prioritize the Madrigal typal, it's best to hone in on the most important, useful Madrigals, and then fill the deck out with stronger strategies.
Observing it purely as a boardwipe leaves it outshone by Day of Judgment and Sunfall, but artifacts are incredibly relevant in Standard at the moment