In 20 moves, match 20 snails. Even if 20 moves don’t sound like a lot for 20 snails, the objective is perfectly achievable without the use of boosters. But hey, that doesn’t mean we can’t use them to help us out of a tough spot.
While the grid is big enough, the thin walls separating both sides make the snails and gifts there impossible to match. The only way to get the objects in there out, is to make room in the very final row in the bottom. At times that might prove a bit hard as there won’t be a lot of matches available.
One strategy could be to focus on special gift combos in the main grid, while making room in the bottom or launching those special gifts against the sides. In the top, the Snail Emitter will spawn a snail almost every turn. Now you should wait for a couple of those snails to appear, as with 20 moves to go, the only way to beat this stage is to match a lot of snails at the same time. And because the matches you generate in the bottom will spawn new gifts in the top, the new gifts can accidentally match with the spawning snails, so you won’t even have to worry much about them.