It's a mixed bag. I've got 40 hours into it, so it's definitely worth the entry price, but it wears out its welcome a lot earlier than the better factory games.
The root mechanics are moderately complex. Not nearly as deep as Factorio or Factory Town, but there's more to them than something like Per Aspera.
The Asteroid Hopping mode isn't much fun. You quickly fill the current map, and then you move on to a slightly bigger asteroid and rebuild your factory from scratch. This gets repetitive really quickly. Worse, you're not advancing much each time - I played it through 3 asteroids, and the 3rd still had 2 of the 5 basic ores locked. I went back to the campaign after that because I was seeing more of the game that way.
The campaign is a succession of puzzle maps. Some of the puzzles are interesting, some of them are trivial, and some are downright tedious. Far too many of them have some very specific gimmick. Often, they disable some specific part of the game, like creating new buildings or blocks, because the scenario would be trivial if you were playing normally.
Despite the name of the game being "factory asteroid," most of the campaign maps take place on a planet surface. Which is fine, building on actual asteroids mostly just means you're playing on a really small map.
Some of the production chains are really weird. For example, making stainless steel, steam, or pizza requires lava. It's not important, even if it is jarring that you're doing things like running power cables made out of ice.
The game has research, but you don't want to bother with research most of the time. Many of upgrades you can research are expensive and not very valuable. It's not cost-effective to spend 3x as many resources on a mine when it only increases mining speed by 30%, and the mine has a limited number of minerals, so you end up throwing it away when it runs out.
All too often I found I didn't install upgrades even if they were pre-researched in the scenario. The main exceptions were technologies that were required to win a specific scenario.
Some mechanics, like flooding to fill lakes, are definitely undercooked. Water spilled on the surface behaves very oddly. Fortunately, they're not core mechanics, they're stuff you'll do once or twice for a puzzle and never again.
It's kind-of 3 dimensional. Most of the time you're really playing in 2 dimensions. You can build your own blocks, and construct odd bridges around your factory with them, but on many maps it's prohibitively expensive to do so. Dumping 100 of anything onto a tile with a "landfill" item makes a new block, but even 100 concrete is a somewhat substantial investment. Stainless steel blocks only take 10 stainless steel, but stainless steel is a high-tech, expensive material. In any case, you're not going to be building a multi-level factory like in Satisfactory.
On the positive side, some of the puzzles _are_ pretty interesting. I enjoyed building the space station where you have to trade for all your minerals - it was a bit like playing a "skyblock" challenge in Minecraft. Complete with the ability to manufacture new real estate for your factory out of those stainless steel blocks.
The developer also seems very responsive. There's not a lot of traffic on the game's discussion board, but he seems to participate there when questions or concerns come up.
