Pretty close to finishing the game, I'll give a bit of a rundown with my experience of it.
Other than it being turn based there's no reason to compare it to Final Fantasy Tactics. Your tank starts with around 8hp and does 3 damage. A standard skeleton enemy has 3hp and hits for 3 damage. A tough enemy has 7hp and 1 armor. I've seen a few people comparing it to "Into the Breach," which it's kinda similar to in terms of unit numbers and stat progression but gameplay isn't nearly as puzzle oriented. I'd compare it more to "Card Hunter" without the deck mechanics.
Characters are preset - a Warrior, a Ranger, and a Mage. Eventually you'll have access to a Ninja/Thief. Character growth happens through level ups, power up "gems," and eventually having access to a shop. Leveling a character will give them access to a character specific list of new abilities or passives (+2 hp, etc.) of which you can pick one. Gems can be acquired through missions and optional objectives which can upgrade your abilities or weapons. Each upgrade is specific to the skill/weapon - a buff/debuff might last longer or a skill might hit for 1 more damage. Gems can be slotted or unslotted freely and you'll want to change your focus depending on what you're up against. The shop will get more items if you complete optional objectives in missions but gear mostly adds abilities, not scales to make you hit harder. For example, my Warrior started with a sword that hit for 3 damage and could be gem upgraded to pierce 1 armor. I eventually bought an axe that hit for 3 damage, gave one skill an extra use, and could be gem upgraded to give a skill that gives +1 damage a free use whenever he kills an enemy. Then I bought some armor that gives +1 hp but lets him walk on water with no movement penalty. Gear mostly just opens up strategic options. You do have some leeway with how you level up, upgrade, and equip your units: your warrior can focus on damage or tanking and can be equipped with a bow if you want.
Production values are fine, I guess. I don't know, I don't really give a shit about graphics. They look okay, nothing terrible nothing great. I wouldn't list it as a plus. Music is okay, a little repetitive. If you require high production values to play a game you won't find much here.
Story... exists. I guess. Big Evil trying to destroy harmony. There's some backstory shenanigans going on with the warrior character. Dialogue is a little juvenile. The characters are constantly wise-crackin. I'm not sure if it's trying to be funny (it's not) or just not taking itself too seriously. Not much there.
Mission objectives have a surprisingly nice amount of variety. Some are kill everything on the map, some are defend a position or person, some are escape. One has a giant monster chasing you that can't be damaged until you destroy some crystals scattered around the map. Optional objectives have decent variety as well. Usually it will be collecting treasure scattered around the map or crates that will add to the shop inventory. Sometimes it will be to complete the mission without having a character die or in a certain amount of turns. Sometimes the main mission objective is to escape from a monster and the optional objective is to kill it. You'll usually have 2-3 optional objectives per map and completing them earns you extra gems, gold, or experience.
I've seen several people talking about endless waves of reinforcements. Nearing the end of the game I've encountered one, maybe two missions that had endless reinforcements. Every other map has a set number of reinforcements. It usually gives a tactical option - you can either try to complete the mission objective before facing all the enemies or hunker down and whoop their asses, then complete the objective at your leisure. Depending on the reinforcements both are viable strategies. Standing on a reinforcement point will not stop them from coming, they'll just spawn next to the spot. Sometimes there are spawners that will continually spawn enemies if left alone but they can be destroyed and doing so is occasionally a mission/optional objective. I suspect that people complaining about this have not played the game. Shocking.
I want to highlight the difficulty of the game, because it is the entire reason I am enjoying it. It has 3 difficulty settings, Easy, Normal, and Hard. Easy you can finish while undergoing a lobotomy. Normal will let you enjoy the mechanics of the game without ever really pressing you to experiment with them. Hard is a challenge. There's a lot of customization with the characters, especially with the gems, and Hard really makes you examine strengths and weaknesses. Typically I would begin a mission, get a look at what I was up against, then restart it and spend a few minutes customizing each characters load out. Most of your better skills have limited uses. They can often get more with gem upgrades but part of the strategy is knowing when to use your best skills and when to hold back. Or whether a skill is worth upgrading at all. By the end of the game you'll have dozens of gems and it gives you a lot to work with - you can make the mage launch massive aoe fireballs or focus him on locking down enemies with debuffs. The Ranger can be specced to healing or raining arrows. Or instead of focusing all in on a couple abilities, partially upgrade a lot to make them ready for several different scenarios. Hard mode will throw a lot at you and you'll have to make use of what the game gives you if you want to complete it. Completing optional objectives is a big factor in this too - if you ignore them the game gets much easier, but every optional objective can be completed on a map's first run and trying to take them on is a very enjoyable challenge.
Ultimately I would recommend the game, basically because it actually has a setting that provides a challenge. Most games I play these days are fucking easy on every setting, or hard for 30 minutes until you access a certain skill or overpowered weapon. Druidstone stays challenging through the whole game and punished me every time I thought I could waltz into a mission without thinking about what that mission's obstacle was. It's not amazing, it's not gonna floor you with anything, but it is fun. If you're on the fence then wait for a sale. And definitely play on hard mode the first time through.