Thank you for trying out our game and for the nice words!
I do agree that the scoring system isn't explained properly. We should likely try explaining it a bit better than just a screenshot at the game page. Potentially a cheat sheet in the game would be very useful.  
It's a type of game where there player is given a very big range of moves to choose from. They have to consider where to draw a line, in what orientation, how many bubbles do they want to affect? If there is a force bubble, they have to choose whether to utilize it somehow, or try to cross it out. Sometimes the best options might be to sacrifice some of your bubbles for a better score.
With our current approach, we want to guide the incentive through the goal of each level. In the current version, most of the times the goal is to reach a certain high score, using the least possible moves. Using different scoring approaches for different levels, it should be possible to incentivize the player to exploring different strategies. For example, the goal in a level could be to maximize the number of bubbles you have at the end of your moves.

Another way I can think to create the incentive of caring for the smaller bubbles, would be to add some more special bubbles in the game. Perhaps a bubble that if you cross, it makes all your lowest value bubbles the highest and vice versa.
Finally, I would have wanted to have larger bubbles occupy more space in the play area, but we didn't get enough time in the jam to implement that too. I hope we can make that now, and perhaps with some cooler looking vfx for when the mirroring happens- also I would like to have some kind of metaballs effect for merging the bubbles and a popping animation. 

Either way, am writing too much! I hope I can get to try your game too soon.