How to get more balloons?

If you are collecting balloons for Coconut's Sky Journey, then basically new balloons are spawned automatically in an open space next to a merged object sporadically - so not after every merge, but randomly after merging items.

Keep merging items to get more chances of getting balloons.

When you gt balloons try to keep merging them until you get them to the top level before redeeming them on the game board. This will get you more points than if you were to redeem them one by one.