As ZeroT2 said, this game is very unfinished and levels just kinda end out of nowhere, without any cutscenes or much dialogue. Once you beat the overgrowth that means you completed the forest level, and more-or-less the same applies to other levels: the lab level ends after you beat the boss there (there's not even dialogue, if I remember correctly), and both the pizzeria and the farm levels are so unfinished that they don't even have a boss.
I haven't touched the daycare level in a long while (because abdl is not my fetish, so I played this level only out of interest to see how developed it was), but I remember that it got updated the most often, so maybe this level has a boss as well.