Quick gameplay mechanic summary based on my playthrough. It is very much a grind to beat levels comfortably so be warned.
Core "gameplay": protect your central base from being destroyed by enemies that will spawn from the cardinal directions of the map. This can be done by using traps or goblins to capture/kill adventuress (as the game describes them).
Capturing vs killing adventuress'(s?): to capture an adventuress, you must either have a goblin that has the ability to capture last hit an adventuress or have them run into a tentacle trap.
Using a goblin to capture has the coinflip of possibly killing the target, as it is not guarantied to capture them.
Using a tentacle trap is "safer", though equally if not more annoying, as you must first lower the adventuress's health bar. It is important to note that the "mental" health/state of the adventuress is irrelevant to capturing the target, as pushing their mental state to 100 just causes the target to gain a buff/debuff/nothing depending on the subject (you can check by clicking on them and checking their "status ailments").
Practically speaking though, the only adventuress's you should be trying to capture are the uniquely named ones, as bagging the mobs only nets you some extra energy.
Traps: there are (generally) three types of traps; ambush traps (which do flat damage), tentacle traps (which have a chance to capture adventuress' based on their hp), and status traps. Ambush traps are the only kind of trap that I would recommend upgrading, as they do flat damage to enemies and will be consistently strong throughout the game. EX tentacle traps are what I would recommend to use to capture the named adventuress', as you honestly do not need them too often. The rest of the traps are generally centered around building adventuress' mental health bar to apply the status ailments. However there are some that help with lowering attack/defense/speed stats, which can be crucial late game if you decide to use goblins primarily.
Goblins: goblins can be obtained by recruiting from the "scout base" or by breeding with the named captured adventuress'. That being said, so far as I have seen, early game breeding works well, but by the end the stats are not good enough and you will likely rely on the scout base goblins.
Important battle mechanics: the amount of damage a goblin does is it's attack minus the adventuress's defense stat.
DMG = Goblin Attack - Adventuress Defense
Traps do "true" damage and ignore the defense stat entirely, which is why I suggest upgrading the ambush trap.
Trap Gameplay vs Goblin Gameplay: I believe it is technically possible to beat the entire game using only traps, I do not believe it is possible to so with only Goblins due to the stat disparity between late game adventuress'. Obviously you should be doing a mix of both, but if you want to rely solely on traps, it is likely possible due to the sheer amount of damage they can do.
Key Tips/tricks:
0. Turn off the Results Window
Everytime an adventuress enters the dungeon or is defeated you will get a notification window pop up. I made the mistake of having it up while played and it easily doubled the time I spent on this game fml.
1. Energy Grind
If you are low on energy/want to grind energy/resources, if you can get 2 goblins with enough damage to one-shot the adventuress on level 1 and they have the ability to capture, you can set them up, one on each entrance and set the game to auto to grind out energy and early resources. Technically you do not need the ability to capture, but it gives you more energy, so generally it would be better to have it.
2. Setting up Manual Ambushes
If you set up waiting rooms at the start of each entry point, you can do manual ambushes with goblins, surrounding and one shotting adventuress' as they enter the rooms. Once you've placed a goblin, it does not require extra energy to move it (unless you send it back to the standby area) though it still does require orders. However orders refresh every turn, so you can rapidly reposition your goblins around every turn if you have the waiting rooms available.
3. Base Layout
I've (hopefully if all went well) inserted the layout of my base that I used to beat the game. Not a single adventuress made it to my core. That being said if the game was a little less clunky and a little more engaging, I would've made my base a complete spiral because I like base building games.
Back to the main point though, in the screenshot I've drawn crappy red arrows showing how each branch eventually leads into the eastern line of the base. This is because in my opinion, it is better to have them trickle in through a single gauntlet than having to build up 4 different defenses on each cardinal side of the map (though I kind of did anyway and then had them connect).
Notice I have my resource building consolidated in one spot that is locked off from the main dungeon crawl, this makes it easier to go for upgrades between rounds, as well as having them just as safe as the core.
Notice that I also have quite a few red rooms, which are the waiting rooms you can move goblins to. This is because I primarily used goblins to swarm weak enemies I could one-turn and left the traps to deal with the stronger ones.
4. Spells
Do not be afraid to use spells (assuming you have enough energy), as they can change defense strategies very quickly, as long as you have them upgraded (via upgrading the core).
Ending thoughts:
I really wish this game was less clunky/grindy, as that is what gives it it's length. (I beat it in about 5 hours with most of it being grind). I do like the freedom of layout building, which you don't see in a lot of these games. I do also wish there was a trap gallery so you wouldn't have to go back to levels to watch the trap animations as well. H content is pretty limited with what the game considers to be 4 per named adventuress. If you're here for fap material, look at a gallery, it's not worth the grind. If you're here for the gameplay, just know there's grinding involved.
if you get stuck at a level, just know you probably need to grind more resources, but if you still have a question regarding gameplay, shoot me a message and I can try and assist. Though I'm not on here too often.