There's not so much routes as there is a "gauge" in the form of a clock that determines your progress. Basically, Tick Tack is set after the Nerine ending and you're sent back in time to when Nerine's dad first proposes to her mom, Sage. Cuz of your arrival, you fuck up time and it's up to you to make things right.
You can "push" the gauge to make Nerine normal, tsundere, or loli and this can be done by sexing or not sexing Nerine's potential moms.
Game is a huge sex romp btw... literally about 90% of the CGs are sex scenes.