Just to give you a baseline, the game is designed to be completed in under 4 hours, so there are no intended huge timewalls
If you feel stuck meaby you just need a change of strategy for the endgame.
Here is a tip:
the power of a release scales with that energy's production rate (which makes the base white tier the strongest), while the duration of the release depends on how much energy you've hoarded. Try turning off the stats autobuy, accumulate a good amount of white energy, and then trigger it.
Let me know if that breaks the wall for you!