I don't think Iran intended to do significant damage, if you mean flattening half of the country. They're responding to a attack on their embassy in Syria. What they showed:
-They can easily overwhelm Israeli air defenses. Israel cannot defend against more waves like that.
-They can target anywhere in Israel. The strikes were hitting military bases all over Israel, or at least targeting them, whether some were intercepted or not.
Israeli's were expecting Iran to target 2-5 sites with smaller concentrated strikes, imo. Almost all of Israel except Tel Aviv area was targeted. If Israeli's escalate and Iran sends more waves towards Tel Aviv, their airports and runways and other important installations will come under fire. Israeli's tonight feel they don't have a qualitative advantage anymore. They can flatten tiny defenseless Gaza but they cannot deal with Iran. Which is they threaten using nukes like the disgusting Nazi savages they are.
Some of areas targeted(unclear how much damage there is now. Israel is not gonna broadcast damage immediately to the whole world and let Iran feel emboldened):
1.)Dimona industrial zone (many targets in this area)
2.) Hatzerim airbase in Beer Sheva
3.) Israeli settlements in West Bank and Israeli government buildings in Jerusalem