While the card not doing anything when you cast it is a shame, you only need one turn with this thing to completely transform your board state
Eight lands in play is the break-even point where you can cast this for free, though you could always run it out earlier, hope it sticks around for a turn cycle, and untap with something like 10 to 12 mana from lands alone
But also a game that someone who's never played a game like this before can pick it up, understand the concepts, and then get drawn in by the characters." Considering how difficult it can be to get your head around Magic or Pokemon these days (there's a reason Magic's head designer noted in an old blog that the company has spent "almost 30 years trying to make a product where people can teach themselves, and its turned out to be really, really hard"), that accessibility is overdue
You can use my general guidelines as a starting point, but all decks will be a little different, so playtesting is the best way to figure it out