The game becomes impossible to continue playing without payment.
"if you dont have enough crystals to buy enough energy then you have to buy crystals with money"
"It's not a real pay-wall, just one where progress can end up painfully slow if you don't pay for boosts etc. You go from upgrading things constantly to suddenly being unable to do so without waiting for days for profits to accrue."
"Certain plants require real-world money to unlock. One plant, the electric peashooter, costs $7.99."
"Additional Flower Pots and Seed Packs, which cost real money"
"The regalia gallery. The devs charged the costume for the confidants. Everyone thought they will get it for free after finished all the chapters."
"Kind of. Super inconvenient energy system that you can pay (spend in game money, which you buy with real money) to refill"