Put up to three MLP characters on a restraining table(?) and stuff things into them until they cum, pass out, or whatever.
That's the whole game, for better or worse.
There's no goal, no currency, no unlockables.
You can attach a cum transportation device to one's dick, then transfer that cum into a different character's dildo, jammed deep into their butt, then watch as the cum slowly bloats their belly to the point of practically looking pregnant.
You can use a toothbrush or a feather to tickle their feet, or make a dildo into a huge vibrating stun gun and jam that into their vagina while they thrash about and eventually pass out from the pain... whatever it is you're into, I guess.
There are a wide variety of characters to choose from, each with their own personalities and fetishes (though it doesn't affect much, it's just to decide how much they like one thing or another.)
Each character has their own orifice elasticity, pain tolerance, and capacity; not to mention the choice of ponies, dragons, gryphons, male, female, crotchboobs or no.
TL;DR: read the first paragraph. What the game does, it does well.