New Game - Letter Quest
It's a letter based game in which you create words to attack monsters across various stages. Every so often you will encounter a more difficult boss fight. There are three challenges to each stage; normal, time challenge & hard difficulty. Each rewarding you with more gems.
You can use these gems to purchase upgrades to basic stats like health, attack, defence or you can purchase new skill books to equip & learn.
It does have in-app purchases for a gem doubler, bonus store unlock & various quantities of gems. I'm not inclined to want to purchase any of these thus making the game easier but there is an in-app purchase for a donate which I will feel obliged to purchase if I carry on enjoying the game.
Unlike Trials Frontier or Tiny Dice Dungeon it has no wait timers thus I was playing for quite a bit yesterday evening.
The game itself is surprisingly free & so far I have not come across any paywall forcing me down the route to in-app purchase.
The developers website http://www.baconbanditgames.com/ is also a very good read & the blog posts go into quite a bit of detail on the development of the game.
The game is also on Steam Greenlight