So does this have a gallery and more enemies than slimes?
Gallery unlocks after clearing the first stage, every time you clear a stage the enemies found in it are added to the gallery.
10 total enemies:
slime
wolf
orc (boss)
goblins
bandit
tentacles (boss)
minotaur
treant
plant bulb (boss)
shadow (final boss)
Basic game flow:
Choose a stage and your girl will autopath across it. Sometimes she'll find branching paths and you'll have to pick either A or B for her to go to. 8 rooms to each stage with a boss at the end. Fights are entirely automatic. Your girl and the monster have time gauges that fill up automatically, when the gauge fills they take a turn. After your girl attacks, she gains 1/5 of her special bar; if it's full on her turn, she'll use her special (just a heavier attack) instead of a normal punch. If she drops below 40% health and has a potion, she'll drink it instead of attacking on her next turn (heals about 15% hp). Losing triggers a sex scene with whatever beat her, then you get booted back to the hub. After a scene, she can give birth (money + a chance to get a charm) and get milked.
Whenever your girl hits an enemy, she'll gain xp (amount is based on number of hits and strength of enemy, not how much damage you did). When she levels up, you get a training point you can spend in the hub. Spend a training point to do a timing-based minigame for a stat of your choice, gaining 1 point per success and getting 3 tries of increasing difficulty per training point. VIT increases her max health (all heals scale off % max health, so this is good), STR increases her damage per hit and DEX makes her turn gauge fill up faster, so she can attack more often than the enemy. Since xp is gained per hit rather than per damage or per kill, more dex = more xp.
Charms can be equipped in the treasure menu to grant passive effects. There are 30 of them to collect and the order you find them in seems to be totally random. They can also be upgraded in the shop, every time you come back to the hub there'll be a random charm upgrade on offer (the 50 gold upgrade increases the number of offers at once).
The shop also has upgrades for milking (each level of the upgrade gives s 25% chance of getting 2 milk instead of one, capping at 100% chance), upgrades for the training minigame (makes the timing easier to hit, 3 upgrade levels) as well as manually purchasing stat points (200 gold per point) and buying hp potions.
Finally, for those wondering what the milk is for; you can use it on the prize wheel instead of money. I believe that's the only purpose for it. On stages 1 or 2 you can encounter a prize wheel, which can pay out - totally at random - with anywhere from 5-250 gold, 3 potions or a free upgrade to a random charm. It costs either 30 gold or 2 milk to spin the wheel once.
And if you're wondering what kind of numbers you need to win, or what to build or whatever; I cleared the entire game with 30 str, 60 vit and 100 dex + the stun charm and slow charm, enemies literally cannot hit me back unless they counterattack.
All told it's pretty short and sweet. Good animations, simple gameplay, good way to kill a couple hours. Not very hard.