It's not easy for idle games to stand out, but BattleLeague Hero makes a solid go at it. This freshly launched title has some of the usual gacha game hero-collecting stuff, but it's more about putting together a strong, balanced army. Between the strategic choices and the colorful anime art style, it almost reminded me of a Fire Emblem game.
When putting together my army, I had to carefully pick different heroes and unit types while balancing their cost. Super-powerful hero units may have impressive, battlefield-sweeping attacks, but they also carry a hefty cost of three or four all on their own. Meanwhile a whole troop of spearmen or archers only cost one.
Once I had put together my army, I put them to the test in both player-versus-player battles and battles against AI-controlled armies in a campaign mode. These battles play out automatically, but my troop selection and placement definitely played a big part in my successes and failures.
I was particularly surprised by the campaign, which was better-written than I expect from these kinds of games. And when not playing, my armies gathered up resources on their own, as you'd expect from an idle game. That said, progress in said story goes slow, as I was quickly gated by needing more powerful troops, and earning those troops (and the gold to upgrade them) required opening time-locked treasure chests.
If you've got the patience, though, and are looking for a more strategic spin on the idle RPG, BattleLeague Heroes is a nice choice.