The game is very grindy. All resource intake is slow and nearly stops to a fault around level 31. The offers are there to entice players to get pass these road blocks, but that only helps for a short duration until the next road block comes along. Considering how grindy it is, 4x speed should not be gated behind a pay wall. The two periods where they give out free energy should be extended to at least a two hour window. One hour is too short. Resource intake doesn't justify time spent.