Let Them Trade

This game is a good entry point for anyone new to economy simulators. The presentation is solid, with pleasant graphics and clean audio that make it easy to get into. The gameplay is simple to learn, succeeding as an accessible and enjoyable introduction to the genre.
However, for experienced players, the appeal might be short-lived. The main campaign is quite brief, and the game unfortunately lacks meaningful endgame content or compelling mechanics to encourage multiple playthroughs. Once the campaign is over, there isn't much long-term challenge, which will likely leave genre veterans wanting more depth.
It's worth noting this opinion is based on the final playtest, as the 1.0 release, i bought, didn't introduce significant changes to these core areas.

bought all of the potatoes from my peasants for cheap. kept buying until price skyrocketed. sold them back to the peasants for huge profit as my peasants started to starve. 10/10 would manipulate the market again

Its a great game - if you know what you can expect or will get.
What you will get: A very relaxed, laid-back, and somewhat easy game. You have a board-game type map. Found your citys, create production chains and buildings, connect them via trade routes. Thats basically it. Just, relax and observe how everything unfolds, how the merchants do their job, how the trade flourish.
What you will NOT get: A challenge, a deep and complex simulation, a fascination story, difficult enemies, or whatever.
Sounds boring for you? Than its not your game. For me, after a long and exhausting day of work - just building some cities, watching how your little wood-empire prosper, without challenges, without action or "save the world"-scenarios is just exactly what is sometimes needed.
However, it took me about 6 hours for the full campaign, so decide yourself if 18$/€ is reasonable for you.

A Promising City Builder with Unique Trade Idea
I played the demo and full game for about 6 hours—almost completed it. The trade-focused economy is a fresh idea and makes earning money more strategic than in many other games. The detailed art and unique level designs are also a highlight.
However, the pricing system needs serious work. For example, tools sell for less than the materials needed to make them, making production unprofitable. Auto-trade struggles to balance prices. Maps are fixed (not procedural), only 4 cities can be built at the beginning, the tech tree is very basic, and traders are too slow—especially across long distances. Faster transport like trains or planes would be great in the future.
In short: a great concept, but the core trade and economy systems need a major redesign.

Ignore the negative reviews. This is literally described as a cozy economy builder - and that's exactly what it is. Little campaign to get you up to speed with the game, and then some inbuilt maps to refine your techniques. Plenty of opportunity for further updates, and a growing amount of custom maps on the Workshop.
This is a cheap game, and you'll definitely get your money out of it!

Already played the demo and I must say this game rocks!
I've always enjoyed these types of games, especially when they don't get too complicated in the endgame. This game is very chill and scratches my itch for building stuff and watching the world unfold.
Props to the devs, great work!

I would tentatively recommend this assuming you know what you're in for.
Let Them Trade is a fairly simple and chill logistics based city builder where you construct and upgrade cities with associated production tiles. Each city can produce its own goods and cities can be interlinked with roads to allow for trade between them to collectively meet the needs of the people in all the cities. Efficient city planning paired with a research tree allows you to accumulate wealth and see the cities prosper.
I found the core experience of the game quite enjoyable, it's a fairly relaxing and low stakes game which you can complete within several hours as it does not take long to complete the research tree and max out all your cities. The visuals are simple but nice to look at, the music is pleasant and the game-play is pretty straightforward. I think it serves as a good game to play whilst you do something in the background like listen to a podcast etc.
I would however say, the game is fairly basic in its current state, perhaps too basic. The technology tree is very brief and feels a tad unfinished, like it should have more options but it doesn't. The game also has a bandit system where trade routes can be attacked but that whole aspect is more annoying than anything else (you can thankfully turn it off entirely). Throughout the game I do keep getting the feeling of wanting more, more resources, more cities, more technologies. Whilst the core game is fine, I feel like the line between relaxing and boring is very fine and Let Them Trade is teetering on the edge.
I think to improve the game moving forward, the devs should add more meat to the bones here, I don't think added complexity will take away from the laid back vibe the game is going for. I think some design decisions need refining as well, I think the individual perks of production tiles you can select are tedious to manage. There should just be a separate page where you can control the global selection of perks for a specific production tile type instead of clicking on them separately, something like a branching upgrade tree where you choose to specialise the tiles for specific purpose. I also think knights should have a patrol option seeing as you can only have 3 at the most and the range of guarding they provide is minuscule compared to the map size. Having them patrol the roads of a certain area seems far more sensical than constantly moving them around.
All that being said, if you go into the game expecting a simple, chill albeit brief city building/logistics experience, you will get that. However, if you're looking for something more involved that you can play for a longer amount of time with added complexity, probably look elsewhere.