Comic Jumper

Honestly its probably easier in the long run to concentrate on these first. Start purchasing these as early and as many as possible because each one purchased adds a % to earned money after every level and challenge. Once all of them have been purchased you can earn 325% more money per level (more than triple) making this and maxing out all abilities much easier and quicker to obtain...

I was able to purchase every last unlockable by mid game (completed the first Silver Age level, and a few challenges).

Also notable Bonuses worth purchasing are the Exclusives. Captain Smiley gamer pic, Star gamer pic, a Comic Jumper premium theme and Bonus Levels for 'Spolsion Man (cost $5000 but gives you 35% bonus by itself!)

PS: If I added them all up correctly, the bonuses cost a whopping total of $39,325. Sounds like a lot, but like I said, buy as many as you can as early as you can and you will have more than enough $$$ for everything in 1 play through!

If you don't want to grind....

This one can pop just by playing the game. If you start off avoiding upgrades and just buy the bonus items you will start to accumulate money pretty quickly. I will put it to you this way... by the time I was able to do the CCKC challenge 1, I had them all aside from a few very cheap concept art slides. There is no need to grind. This will come very easily during the first play through and certainly much more enjoyably.

The method i found that was easiest for me was to load up the challenge Cutie Cutie Kid Cupids Challenge 1. Every time the challenge is completed you will get 18,000 - 20,000 credits.

Learing the way the enemies spawn and who to shoot first helps a lot, also the more bonuses you have bought the more credits you will get!

After every bonus is bought you will get 20,000 credits each time.
This challenge only takes 3minutes!!!!!!

The overall total of buying every upgrade and bonuses was around 200,000 credits for me, you will get most doing the story

If like me you didn't buy any unlockables during your first playthrough of the game then you can use this method which works fairly nicely.

If you have any money left over, buy as many unlockables as possible.

Do Challenge 2: It lasts approximately 1 minute 10 seconds and pays a subtotal of around $2200. Multipliers can increase this to up to $10000.

After every 2 completions or so, buy more unlockables to increase the score multipliers.

Oh, and turn on Target Assist just to make it a tad easier.

Luego de llegar a la base, una forma para poder hacer dinero muy rapido, es jugando los desafios, especificamente "las aventuras del Capitan Smiley Desafio 2". en el pueden hacer hasta 1000 por si mueren antes de terminar la etapa, pero son pocos segundos y bastante dinero, juntas un resto y despues guardas y van a comprar bonificaciones, cuando las tienes todas, tienes un bono de 325%

Ademas de obtener este logro, puedes sacar el de todas las mejoras al personaje.

There is a great Challenge that is available early, and can get all the money you need for all the bonuses and upgrades in about an hour. The Captain Smiley Challenge #2 is about a minute long, and can net you $2000-2500 per run. You need about $40,000 for all the bonuses. Hope the video helps!