Greetings, aphrael2. I usually don’t post criticism, but seeing as how you’ve asked for honesty, I’ll give you my fullest opinion.
What you’re doing right: The faces and expressions are amazing. Very cute, very vibrant. The ticklee has a laughing expression, which I always like, but you can still see she’s at her ticklish limit. The expressions on the ticklers’ faces show that they really, really enjoy what their doing, and if I’m not mistaken, the ticklee’s bra shows she’s also enjoying the tickling. The torso proportions, aka, the breasts, stomach, hips, and thighs, are all very well done.
What you’re doing wrong: First and foremost, the ticklee’s arms look a bit noodlesque, even for an anime character. Too long, and too bendy. Also, the sheer mass of girls in this image detracts from the actual tickling. I’d say, even for a mass tickle picture, you’ve got two too many girls here. The dark haired girl in the middle could definitely be removed to provide more space, as well as the only girl who is tickling the ticklee from the front. The hands and feet in this drawing could use a little work, though those are usually the hardest part of any image.
What I’d like to see: Keep in mind, what follows are not general ideas, but rather my own personal preferences. Take them with a grain of salt. I’d actually like to see more sole shots, seeing the bare sole of the foot being tickled. The bondage we see, the metal straps, seems a little more painful than restraining, so I’d really like to see more comfortable bondage, like padded cuffs or soft rope.
Now, all that being said, this is definitely an amazing first picture! I am truly impressed by your artistic ability, and already love your style. I can’t wait to see what you come up with next. Well done!