Hero Squad is just another mobile fantasy gacha/idle RPG. Still, it stands out due to its aesthetics and a large number of features.
When it comes to graphics, this game uses 2 different approaches. During the fights, there's a 3d scene with a far, static perspective camera and stylized characters. Still, you won't see many details there (unless some giant dragon occupies several tiles). Fortunately, outside battles, almost everything is drawn using high-quality, polished 2d art.
That goes especially for character design. Despite the limited collection of heroes, every one of them is unique, to the point you won't be able to select your favorite. Beautiful elves, dark and mystic "Cambions", jolly dwarves, or crazy orcs - all thoughtful and special. Not only they're nicely drawn, but also smoothly animated - and voiced. The backgrounds - including blurred ones - might be simpler but still, look perfectly fine. The UI might look a little overcrowded at first, but ultimately it's finely crafted and pleasant to use.
Hero Squad features a story that you'll follow as you progress in the campaign, scattered into short scenes. Yet, the most essential part -fighting - takes place afterward. Battles are played pretty standard way - using turns & full auto-play. The nice thing here is placement - you're given 3 3x3 boards, with some already taken by enemies. Proper positioning might affect what heroes will be targeted first, or even which ones will be hit by specific abilities.
Progressing in the campaign is crucial, as it results in higher idle gains - the core of every idle RPG. Unsurprisingly, there's much more to do than a campaign - towers, bosses, arenas, challenges, or missions. You can also join a guild for an additional set of features, like bosses or assignments, and there're cross-server activities too. What's more, this game comes with a steady stream of new events, each with several sub-features or whole new mechanics (like dice board).
Strengthening your team looks just like in most similar games. You can level-up heroes with common resources or equip them with loot from idling (or auto-crafting). Levels are quickly capped by hero grade, and for this, you'll need gacha hero shards. The game is pretty generous when getting those shards, so you'll frequently be drawing them bit by bit. Additionally, you can use a relic system to get even more powerful or put heroes into the academy to make more heroes useful without grinding.
The game is free (and without ads), but you'll have more than enough occasions to spend real money - especially as there's a VIP system. Aside from premium currency and various offers, there are multiple "battle passes" to purchase.