Storm Casters is pretty amazing. It's an action RPG on iOS with collectible card mechanics, level-ups and a bunch of different weapons and items to play with. I had a ton of fun during my time with this game because it blends solid gameplay and does not mess too much with the freemium tendrils that could have been stuck in every aspect of the game.
Let's start with the two things that annoyed me in SC: Even with four hearts of maximum health, you always start with one and if you get hit before finding a completely random heart refill, you die and you have to go through five menus and change the three cards you had, even if they were awesome. It's annoying, why don't you start with full life? I'd rather be able to pay some coins before each run just to start full life. Also, the game becomes a bit too hectic when you get to later levels where tons of enemies and projectiles fill the screen. The game is very good with touch controls, but not THAT good.
A cool thing in SC is that it plays like a twin-stick shooter, but you always auto-aim at enemies, which is perfect for iOS devices. It makes it a bit harder to destroy barrels when enemies are around but otherwise it's much better than having to choose where you're shooting. The different weapons feel varied enough with bouncing shots, three-way shots, piercing shots, rapid-fire shots, etc. You also have a few one-use items like bombs, potions, and they help greatly against enemies and bosses. The enemies are varied enough and the bosses are challenging - especially the ranged ones - without being too difficult.
For completing levels or leveling up, you get chests that contain gold - to upgrade your character - gems - to buy card packs - or cards. Gems are the premium currency of SC, but you find them at a steady pace and you get enough cards normally to not bother with buying too much packs. You can also use gold to fuse cards together and you can sell them when they get to maximum level. Cards do many things, they increase your odds of finding certain items, they give you more gold/chests/experience from enemies, they give you more time to complete the dungeons you're in, they increase your stats... It's fun to mix and match the three cards you can bring with you. So yeah, Storm Casters is pretty fun, there's no denying that.