I'm enjoying this. Bear in mind that I'm fairly open to freemium games, though I never buy consumable IAPs so you can interpret my words according to your own values.
There is an energy bar and there are dual currencies, both purchasable. That's the ugly side out in the open already. Whilst I'd never try to defend their existence, they're relatively forgiving in this model. The energy bar is refilled on levelling up and so far, I've levelled after every dungeon so I've not come close to running out. I'm sure this will change later on but levelling also brings expansions to your energy bar itself, it's all remarkably generous for the freemium ethos.
The currencies are just as freely given. Gold, the most plentiful consumable, is used to buy random item packs of low rarity. So far, my exploring of an hour or so has given me enough to pick up three if them. The second currency, crystals, are used to purchase rare item lucky dip packs. You need five crystals and so far I've bought one and I'm close to a second. It might not sound too amazing, but it is massively fairer than most freemium models I've encountered.
Anyway, it's the gameplay that matters most. It plays a bit like a linear Dungelot, you navigate a clouded dungeon by tapping veiled squares until you encounter a chest, monster or other interaction. Combat is a turn-based vaguely strategic affair in that you chose to make a light attack, block or perform a heavy attack that takes turns to recharge. Enemies signal the attacks they're about to make so you'll know when to block. There's signs that you'll be able to add in other moves later, which would be nice as it's pretty simple otherwise.
The amount of loot is ridiculous and definitely a highlight for me. Most two minute dungeon sprints will provide three or four pieces of equipment that can be equipped, levelled, fused or broken down into materials to power other items. It's a bit too easy to over level though, I don't know if I've just been lucky with the equipment I've found but most enemies die in the first hit - it would be nice to have a bit more challenge, but that's just personal preference.