So, a bit of context to start with: I play chess fairly well and I know enough of the original language to understand the intent behind the... story. To give a quick overview: it's clear the developers tried and put in quite a bit of work, but I can't recommend you go to Steam and buy this. I don't really recommend it for free either. It's not a horrible game, but it's flawed in several big ways.
So what is Sex Chess? It's a lewd version of Battle Chess. Or I guess a remake of Love Chess if you remember that obscure title. It's a game of chess where pieces have unique animations for "taking" each other. The concept is quite good if you happen to enjoy chess. The models are good too. They are obviously where the majority of the work and budget went. They're both appealing sexually and unique enough that you can still recognise each chess piece. The animations are okay too. They're done with quality, but here is where we start to run into some issues.
The animations are basically all that there is. There is one for each piece of each color taking each opposing piece. Sounds good, right? Well, yes, but they're also just a loop with some variations. There is no progression, there is no orgasm animation, there are no special animations for winning or losing besides the nightmarish devil TV animatic that I can't understand the purpose of. There are no sex animations related to the story mode either. Oh right, there is a story mode! Let's talk about that.
The story mode is easily the worst part of the game and if you happen to download or buy this thing I recommend never touching it and just doing single player skirmishes against the AI. (Though you can unlock the entire gallery if you complete one mission of the story mode.) It attempts to have a story about a confrontation between an angel in hell and Satan, but it's neither interesting nor erotic. It's two cutscenes and a bunch of voice quips of the devil and the angel arguing as you play through the matches. The English voice acting is quite bad. The angel is bland and the devil's voice is frequently distorted with unpleasant noises. I haven't checked the Russian audio, because again there is nothing of value in the story mode. The devil keeps making crude poorly translated regional jokes that were never funny to begin with, and the angel just keeps rambling about how much he thinks everyone should forget games and serve the Almighty. It's not a very engaging exchange. Sometimes Satan tries to comment on the match or give tips about the additional gameplay elements, but these almost always don't actually match what's going on on the board. It all ends with a cutscene that I honestly wish I never saw. But okay enough about the story, what about the chess?
The AI is very dumb. I have a suspicion the devs developed their own chess AI to fit the new mechanics they added, which would be admirable, but it still makes the AI dumb as rocks. I saw it make a move that resulted in a checkmate in 1 twice. No normal chess engine, even severely handicapped would do something like that. Does the addition of spells help elevate the gameplay? I can't say because I never used them. I didn't need them in normal matches. The AI in the last story mission does start cheating like a motherfucker with these, but by then you no longer have access to them. It results in you having to play down two rooks which actually made me lose once, but I beat the scenario on the second try. There are no AI levels either, there is just one AI and it's not good. I didn't mind the slower movement of the pieces as much as other people, but I can confirm it takes a while for them to get moving.
In summary, I like the idea. I hope the devs do more in the future. I hope other devs try this again. Battle Chess was great and making it into an adult game is a no brainer. Unfortunately this attempt falls short in almost every respect save for the actual models. It is best experienced as a gallery of 3D animations rather than through actual play.