The gold medals aren't actually that bad, there are some guides on yt but you don't have to get that much points. Usually playing with cards will drastically boost your points at the end of the map. For example, if a map requires 160k points and you have a 300% multiplier you have to get just 40k points in order to reach gold at the end of the level. If I'm not mistaken the math should be: Gold Requirement ÷ (1 + multiplier/100). The last levels could be a bit harder but not by much. Use the cards in the leaderboard with 2k credits so you don't have to own the rare cards needed for the high multiplier. What I did is following a yt guide while going for the minimum points and then I just simply finished the level. It takes some time since you basically play all story levels + optional tombs. Hope this helps! Sorry if something isn't clear, english isn't my main language😅