Game is nice, at least in a gameplay sense, the hentai part is there just as a lure.
That said, anybody has good combo tips? what's the best weapons? I've been playing a bit but most of the time I can't tell if the upgrades are effective or not.
I can tell you some of my preferences, no idea how good they are. I have only beaten the first 2 difficulties, so my tactics might be pretty crap for the two hardest ones.
The machine gun, with the mini gun upgrade with Chain and Shrapnel are pretty nice, it creates a very nice bullet storm if you add projectiles and shot speed as well. Adding a second shrapnel boosts the shrapnel shot damage 100%.
Can't remember the name of it, but the shield weapon you can get is awesome (as a secondary weapon, don't pick it as your primary) if you get the eliminates projectiles mod and you take the upgrade that makes it an always on shield. Adding range upgrades to it makes it an excellent defense weapon.
The charge shot with the black hole upgrade is pretty nice, the final upgrade for it makes the shot an aoe detonation when its duration expires. Shot speed, bonus projectiles, and whatever else you want to add to it.
I have only used the Nuke special weapon. The fire upgrade is awesome when you pair it up with range upgrades, duration, projectiles, and corrosion. The heavy nuke upgrade feels pretty meh to me.
For the passives, I always take crit chance, shot speed, exp bonus, and damage. After that, personally, I take damage reduction and movement speed. Adding the heal mod to the mini gun and the HP regen passive is a nice survival combo if you are getting smacked around alot.
Edit:
I started on the expert levels and they are pretty rough and it feels like I beat most through pure luck.
Bazooka with Ammo mod upgrade and Charge shot with black hole feel pretty solid to me and they dish out good damage.
Just unlocked my first Master level and it is pure hell, I can't level up fast enough or boost my damage enough to come close to winning match.
Unlocking things actually seems to make the game harder, since you get bombarded with MORE upgrades and options. Banning and refreshing will be your friend, so keep a little cash on hand when you start a match.