When I coded my BlitzMax edition of NeonPlat Adventures (Still online, still free, still available, still awesome, still getting the odd blog post on sites!) I threw things in, wherever they seemed appropriate.

I coded randomly, as I usually do.
I didn't worry about memory issues.
I didn't even give a munky about how many sprites were hurtling all over the screen. (My 2-year-old framework takes care of that.. Hit F12 for your system's stats.)

As I attempt my conversion to iOS, I DO have to worry about these things..
The first step was to convert each character into it's own tiny little spritesheet.
What used to be a set of 5 640x640 pixel images, each filled with 10 characters, each with 10 slots for animation (of which I generally used just 7 due to my lazy art skills!) has now been reduced to 50 120x120 (240x240 for retina) pixel images, each with 9 slots for sprites.

A huge reduction in memory requirements when you only ever need 5 baddies per level.
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As I began to code the AI stuff, something dawned on me..
First off, I need SIX baddies, not 5.
Pinko is also a baddy, and he cannot be missed out!
So, there's another chunk of memory used.

...
Then I remembered the Boss.
I hadn't considered the boss as a separate enemy, but.. yup.. there he is.
And what's he throwing?
Oh yeah, baddies that aren't necessarily those that were chosen for the level's baddies.

... BAH!!!

Expect iOS baddies to be changed somewhat, so that they spawn the level's baddies, and not extra sprites that I also need to throw in at the last minute.

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Coder's version..

Because I've reduced the number of enemy per spritesheet to single baddies, I'm now having to have 7 Batch sprite thingies, because each one's got a different baddy.
That's alongside the tilemap one, and the pickups one, and the particle one, and the objects one..
I'm going to attempt to piece together the objects and pickup ones, although I've no idea how well that'll work out... Knowing my luck, I'll probably end up with thrown weapons vanishing behind the coins or something stupid like that..
grrr..