TLDR: Fun game that relies on RNG to frustrate and artificially lengthen the play time. No progression except unlocks for a difficulty that is clearly designed to screw you over and over to make the game seem like it has much more content than it does. It has great deckbuilder legs, but completely fumbles with no progression and RNG that is painful and doesn't respect your time. Pick a roguelike that respects your time. There aren't enough items, synergies, or unlocks to make my 15th run that takes 45 minutes - 1.5 hours fun. Many builds aren't viable. I regret how long it took my wife and I to see that it was like a pure lottery game and has almost no real content or balancing compared to what it tries to be.

You only unlock items by beating a run with a character (of which there are many and they are often lousy balance too). I believe you also have to have it on at least "Debt 1" difficulty. It starts you on difficulty 0 and that seems to give nothing. I wasted many runs not understanding that and completely wasting my time. I also wasted time on 10+ runs with characters sometimes only to be one shot by a boss that does 156 damage (you have 100) on turn 2 or 3.

Items are bafflingly powerful or useless. Characters are bafflingly powerful or useless. I want to see what the game has to offer but I hate playing it now.

Many items are worthless. Many items are mandatory. Most builds that win are the same. Frost is always mandatory. There are about 2 builds that hold up mostly by using the same items and the same results. There are many fun items that are useless. You will either breeze through the whole run with 500 gold and upgraded purple gear or you will wait for RNG to slap you. Sometimes both.

Example: Your character has 100 health. Last boss has 1k + health. He also hits for 50+ and gets stronger. If that doesn't do enough to tell you the balance sucks, I don't know what will.

in terms of fun level, I'd put this somewhere between idly sitting in silence at home and reading a magazine at the dentist's office while you wait for them to call your name

It's simple. It's straightforward. Lots of characters and challenges to keep things interesting. An easy pick up and play at your own pace relaxed environment.