i played the first 2, but this one i just couldnt figure out. the english is too bad to help and there seems to be important stuff like somehow recruiting enemys by doing something (idk) and putting them into equip slots or something, some rpg combat element.
tl:dr im too stupid and after 10min of not getting to any sex scene i shut it off. i liked the first 2 parts more as its basically just pixel sex whenever you want and nothing else.
Basically, Tillday can use semen to make clones of the monsters you fight in battle. As their health is lowered, the chance your sex attack (second combat option) will work increases. There are more powerful versions of enemies that your sex option doesn't work on, so you have to defeat them. Your monster allies can be leveled up by spending money, or having sex with the same enemies again. When they reach max level, you also get a second, more powerful version of the same monster. Going for sex attacks to level up is generally harder, but since you also use money to unlock skills they are worth it.
When summoning monster to attack, the conveyor at the top of the screen advances by one marker for every attack. You can put various skills on this conveyor, and if your attack advances past a marker with a skill on it, it will activate. Enemies can also use these skills however, so you need to be careful how many attacks you perform in a single turn, so that you don't give your enemies the skills instead. The conveyor loops, so you can use skills multiple times during a single battle.
Monster allies are in multiple classes, but they're less confusing than they sound. Power types have more attack than defence, support have more defence than offense, and balanced are equal. The only important thing is that support monsters double the effect of skills. So if a skill increases sex attack chance by 3%, if a support monster uses it it increases to 6%.
Its actually really simple once you start playing. The combat is way less sex focused than the second game, but I actually find it quite fun. If you like your games a little grindy, you'll enjoy it.