Pacing was okay. If I was overwhelmed it was because I didn't conserve ammo properly. The game could use some things like shot upgrades. Piercing shots that would allow me to more easily conserve ammo might've been useful. The game seemed to randomly assign extra ammo to a gun, hence gun two had more ammo than it ever really needed, whereas gun 1 was empty for a long while.
Another issue is the functionality on the airstrike (which, by the way, is actually a SAM rather than something that actually flies over and attacks, which would have been very useful as well in a crowded field to maybe have something that knocked the back row out of the enemy attack and I had to only deal with the closer ones). Obviously the game has a lot going on and the airstrike is triggered with a click of the mouse. This becomes an issue because there were many, many times when I would be shooting down enemies, and I'd go to click a balloon to activate an explosive or gain ammo, and just that click to get more ammo would happen like a split second after I gained another SAM. So without warning I ended up sending a SAM to the same site that I just blew up a bunch of enemies with a blue balloon and wasted the thing on dead space. Very frustrating, I'd have preferred that SAMs get some other method of firing that would make it easier to use without accidentally wasting it.
The game works, it's really just those couple things, but it's not something that makes the game unplayable. Enemies stay in your line of fire long enough it doesn't become unfair, the music fits the pacing, and the difficulty curve is just enough to get you adjusted to the reflexes necessary to go farther in the game. Graphics are big, colors are bright, I have no problem seeing what's going on onscreen, even if I wished sometimes for a few more milliseconds to react.
I like it.