There's a NG+ option in TW but it seems like you have to start all achievement progress over again (people beaten, panties stolen etc.). What's the upside?
You can actually keep pretty much everything, including panties and your current completed achievements. Only things you always lose are incomplete achievement progress and any girl improvements/relationship stuff (They get permanent ENE/STA boosts from sex). You even keep your furniture upgrades by default. You can also sacrifice skills to gain more permanent max TSP when you newgame+, and that's the only way to go above 4k permanently without cheats anyways.
I would recommend doing all the combat quest (and maybe unlocking Almighty Pregnancy) before newgame+ though, redoing that stuff can be a major pain. If you want, you can save your achievements globally as well, so you can start a fresh character with achievements (In that case, you'll lose stat improvements and skill and such).
Edit: Apparently there were a ton of newgame+ bonuses added since I last checked. You can now set custom races on newgame+ now too for your players or your lovers (Some appear to be locked out from the player, like Maid, Vampire, and such atm). You can also buff previous lover's stat and modify them a bit, so I guess you don't have to lose their boosted STA/ENE anymore, which is nice (It at least allows you to raise their stats up to 2k STA and 2.5k ENE, so no more instant pass out Patchouli, lol).
Also, not sure why, but we now get some VIG boost for newgame+ing, on top of keeping our achievement boosts of course. I went from 2212 vigor to 3300 when I just tested it, weird.
Btw, new full version just dropped:
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