The aesthetic choice to zoom in after shooting and then tick off each enemy one by one really sold this for me. Lining up a fireball and getting a 6 enemy combo is very satisfying.
Some of the enemies appeared en masse, but having more enemies didn't always affect things. For example, it doesn't much matter if there is more than one frog, since they all fall at the same time. The big/small frog difference is neat, but because their cycles are of slightly different lengths, a "beat frequency" effect can occur. The "Frog Gauntlet" level is made easier if you bring the frogs all the way back to the start, as by then the two different kinds of frog cycles sync up. Not sure if this is intentional.
The explosion zoom was one of the first things that was worked on. We weren't sure how fun the core game was, so to convince us to work on it more there was some time spent getting the zoom and pop-pop right. Afterwards, it felt a lot more rewarding to work on the game.
The game design sort of painted itself in to a wall early, in regards to Frogs and having more enemies. When your only action is immediate victory or defeat, the actual amount of enemies can't really make a difference. Maybe with more brain-time, we could come up with more meaningful enemy groupings.
Thanks for playing, and for leaving a detailed review!