Okay so this is how I would describe it. Hopefully you get really clean pills on your first try like I did.
At first you kind of get that anxious, tingly feeling in your stomach on the come up. And it sort of builds from there. For me, after that phase passed it hit me like a ton of bricks. I stood up and immediately felt something was off. I felt really floaty as I walked and my head kind of felt floaty as well (I guess from all the chemicals being released). Your touch is heightened to the max and the slightest touch will feel extremely good, kind of like when your having sex and you can't get your hands off that person. Thats why people tend to give massages, or head rubs, or even start rubbing their face a lot lmao.
The body buzz is amazing too. Picture your orgasm at its peak, but lasting for about 3-5 hours. I read somewhere that MDMA releases the same chemical, Oxytocin, which is what releases during an orgasm, giving you that loving feeling towards others and just the plain ol' orgasmic rush (don't flame me on this). Plus with all the serotonin being released you literally feel happier than you've ever been in your life. The happiest moment in your life x10 with a million-dollar-lottery-winner-feeling is how I describe it

. You become extremely social and have this complete love for everyone around you. Music flows through your body with every beat and its almost like you can feel it. Which is why I think a lot of EDM artists use a lot of bass in their tracks cause it sounds AND feels so good while rolling :D. The dancing part I think has to do with the pills having a little bit of caffeine and amphetamine so its good to have the majority of the pill with MDMA and a little caffeine to give you that urge to stay on the dance floor.
As for visuals, you see tracers and move your eyes really quick sometimes because of the eye wiggles, and it just blends together. Hence the glow sticks and light shows at raves. I guess thats it. Its a really clean high, not something that clouds your mind like weed and alcohol does...that is at the right dose. You can get really "floored" if you take a good amount and end up just sitting your ass down and talking instead of dancing around.