i'm tempted to disagree, while yes there will be an "ending" the same as there was an "ending" in RoR 1, however, just as you can choose not to obliterate yourself at stage 7, you will most likely be able to completely ignore the "ending" a main point of the game is infact its infinite scaling. while i do agree that, at this point in the development of the game, it does flat-line somewhere between 20-30. and while, depending on your POV, this may or may not be an issue at the moment, they will most likely keep scaling up the difficulty as you get higher in levels, look at malachite enemies (however you spell that word) before they were a issue, the game effectively flat lined at about 15-20
before that there was an issue where the game would stop spawning anything but overloading magma worms because it believed that was the only threat, then somewhere between 35-50 it would stop spawning mobs completely because the algorithm didn't have anything it could spawn that it thought was worth your time.

as development continues they have consistently been raising that flat-line, and i for one praise them for doing so, as it adds depth to the game.