via 500ish (A medium blog):

So, again unlike Super Mario Run, Sega has opted to let users download these games for free. And you can play them for free — as long as you’re willing to sit through some truly annoying and invasive ads. We’re talking interstitials, video ads, long ads, short ads. No format will go untested here. The only commonality is that they’re dreadful.

Sonic the Hedgehog was one of the first iOS games I bought. It was $5. Worth it. I’m legitimately annoyed glancing over seeing my girlfriend playing a freemium game with a huge banner ad taking up half the screen. I’ve literally thrown a dollar bill at her saying “please just spend the $1 to disable advertisements. I’m begging you”