So about that bat gang.
After beating the game, I decided to max out bat gang to see how much distance it would lose me.
It turns out the answer was: none. If anything I gained a little. Playing with bat gangs all the way up mostly just makes it play differently. Instead of chaining meteors, you rely on the bat gangs for speed gains and just try to keep from falling below bat level. This means you have to spam click even MORE, but it also gains you money faster, so, evens out?
Mind, I would still recommend to the developers to change it from setting vertical speed to adding to it, but it's not as dire as the comments made it sound.
This is very entertaining. ^_^
One thing I'd say is I think there should be some upgrades that help you start the chain reaction, rather than only ones that help it be more epic. For example, a "more ships" upgrade, or one that makes fast ships show up more often.
Also, it is my opinion that the last max combo should be an even number, so that it hits ships to the left.
Finally, I noticed that the special waves reset your combo to ten. I can understand them using a combo of ten, by why not have them remember?
Also, occasionally in the middle of a chain reaction I see a combo of like 3 and I don't know why.
So, this frustrated me for a while; but, you CAN get back to the main area after beating the final boss (to get the rest of the songs). To get through the section with ups and downs and lava, you have to jump right before entering the first down field, then you hit yourself on the spike enemy and can glide through the rest of it.
It's harder than it sounds, though.
The secret seems like one of the most interesting parts of the game to me. To be able to feasibly find it, you'd need at least three disobeys... but if you have only disobeys, it isn't there at all. (Probably you need to have not jumped into the initial spikes.)