I just played through your game and finished it.

Overall, I liked the idea, but found that since you can focus on one resource at a time, you can use multiple snails to string together telekinetic paths to make a track right to their destination, then delete all the snails and do the next resource. Once I realized that a telekinetic field didn't have to be near the snail projecting it, I rushed through the levels.

Maybe include a difficulty option, which limits the distance a telekinetic field can be from the snail?

Another idea could be to include a rating system, where if you complete a level like I described above; you pass, but to get gold; you need to keep your snails on the board without removing them and maybe do it under a certain amount of time?

I also think it would be a good idea to introduce different concepts every few levels, just to spice things up. Maybe snails that can only manipulate specific resources? Maybe a snail that shifts the levels default gravity direction? I'm not sure, but I think more variety in snails can only be a good thing.

When I was playing the game, I just happened to be listening to some "calm piano" on youtube and I think it actually suits the game. You probably already have an idea for the music, but I figured I'd mention it just in case you haven't settled on a style and need some ideas.

Hopefully this isn't rude, but I like snails and saw that the shells had dark outlines, as did some of the tiles and the map tiles also had slight shading to them, so I quickly touched up the snails to see what they'd look like with additional dark outlines and a small amount of shading. I think they looked nice in-game, so you can have them if you want.

Unfortunately I don't know much about selling games, so I can't really help with that. I guess that if I was in your position, I'd start researching other puzzle games that are for sale and compare what they offer for what price.

Best of luck :)