Google and Apple aggressively push developers to use IAPs rather than up-front paid games, and often won't feature games & apps costing more than 99c. They incentivized the current market.
I think the demo/trial model is still very reasonable. You get to download the game for free and play a level or two and then you need to purchase the full game to continue.
Of course the problem is that it's sometimes a bit hard to tell apart games like this from the P2W micro-transaction shovelware junk
On the app store page for the game, you can see all of the in-app purchases available. If there's only one for the full game, you're safe. If there's a bunch of different coin/whatever purchases available, stay away.
