The same just happened to me!

Worked really well even though I didn’t have all the cards (I replaced all the missing ones with 0 mana 1/1s), thank you!

Yes it is a game changer. It is sometimes even worth to keep it at the Mulligan phase. It instantly creates a strong board (because of your minions’ card text) and will often swing a game back into your favor. It is a very good follow-up for your board clears.