Yo! We're the devs of Towelfight 2 and Quadropus Rampage. Thanks for the shout-out!
With regard to the concern about "free" -- we sympathize completely. There's definitely a lot of hate out there toward the freemium model, and with good reason. "Free" typically means "we're going to put roadblocks and ads in your face and extort cash out of you until you pay up or quit." We don't think that's acceptable. We've tried to be very conscious of the things we dislike about freemium and to avoid those things outright. And there are plenty of freemium games out there that do an amazing job (LoL, we're lookin' at you).
For starters, we aren't doing ads. Many games spam you with ads until you pay, which makes sense from a business standpoint, but makes for a terrible player experience. Plus, you aren't gaining any value for your dollar as a player -- you're just paying not to be hassled. We aren't doing that.
So Quadropus Rampage's monetization will be solely based on IAP. Our philosophy for in-app purchases is that the player should never feel like they need to spend money on the game, but they should definitely feel like they want to at times. To us, that's the key difference between IAP done well and IAP done badly.
Quadropus has a boatload of content to unlock, so that you are always progressing toward several goals at a time and never feel like you've hit a "paywall". We have seven unique upgrade tracks to make your Quadropus just generally more powerful, and we also have more than 20 "Masteries", which are achievements that, once unlocked, allow you to choose skills that make you more powerful. You can spend money to accelerate the unlocks on any of these things, but you will always be very close to the next unlock, so there is a steady stream of character improvement even without spending money. Plus, you'll be unlocking masteries and upgrades in parallel, which brings lots of quick character advancement. And to top it off, you can get up to a 50% discount on the unlock prices of masteries if you have made progress toward finishing the achievement.
The reason we moved to a freemium model for Quadropus Rampage is simply that paid games have a much harder time attracting a large audience, especially for a new studio with no name recognition. For example, here are the numbers for Towelfight 2, to date:
2,651 iOS Sales
1,538 Android Sales
2,438 iOS Pirates
34,091 Android Pirates
These numbers are dwarfed by the size of an audience we could get with a free title. Plus, over 95% of our Android users and about half of our iOS users pirated the game, likely because it costs 99 cents. As it turned out, lots of people wanted to play it, but very few people wanted to pay for it. We made a free game -- we just didn't know it at the time.
While it's great that the pirates are playing the game, and we're happy for the exposure, they are operating "off the grid". That is, our app rank doesn't jump up in the app stores when a pirate downloads it, they can't review it, and they tend not to contact us for support if something goes wrong with the game. They play the game in the shadows. With a freemium title, we can try to move some of those people into the light so that we can interact with them as active fans of our games. We're hoping that Quadropus Rampage can accomplish this goal.
I hope that alleviates your concerns!