The game becomes impossible to continue playing without payment.
"There are three cars in the game that require the player to spend real world money to use. Two are $1.99, one is $4.99, meaning if you want to collect every car in the game, you must spend $8.97. While the $1.99 cars are comparable to the free cars, the $4.99 car is an absolute monster with the highest acceleration in the game and a decent top speed to boot."
"CANNOT breed more Peridots without buying nests, and nests all cost money. Once you have used a nest for a Peridot you need another to breed again."
"The last three levels are a mobile-only addition to the game and their difficulty is notably, deliberately ramped up far past the rest of the game, necessitating use of in-game currency to perfect or even complete the levels."
"It depends to what you mean by payments to keep playing, you wont be locked out of the game but you wont be able to enjoy the game, thus you will quit with disappointment feeling conquering you."
"The game only allows you to play as the first class in the first dungeon. To access the full game, the developer requests a one time payment of $8, which is very reasonable for an solo-dev indie game."
"You can revive once by run (seems there is a daily limit of revives however), by watching an ad, or spending premium currency (15 gems). You can play more by refilling energy (or waiting)"
"sometimes you basically cant play the events without paying because sometimes more expensive event registeration has tickets that you cant get without paying or takes a really long time to grind for and most of the time the cheaper registeration is not worth playing and has really bad rates"