I stumbled upon Unnamed Space Idle about half a year ago when I saw one of my Steam friends playing it and decided to give it a go too. 6 months in I am amazed how fun and well developed the game is and its still growing at a steady rate.
First thing that stands out it that it have onscreen combat mechanics, where your ship fight enemies, which is a cool feature.
Game mechanics are split in different tabs that will open gradually as you progress. There are variety of mechanics there and the further you go, the more complex your runs will be.
Another cool thing is that most of the actions can be automated in the long run, which removes the need of manual repetitive builds and allow players to focus on important stuff.
I like how achievements add some incremental bonuses to the stats and overall multipliers mechanics.
Progression is pretty slow, but at the same time its consistent and you always get something upon prestige and have that feeling of progression. So far I've faced some walls that could be overcome with a proper build (If only I knew that wiki had all those builds back then https://usi.game-vault.net/wiki/Stage_Pushing_Builds).
Overall the game can be played blind without any guides and players can progress just by reading the description and trying things out, which is great. If someone want to minmax their progression there are lots of guides on the game discord https://discord.gg/USI and the wiki https://usi.game-vault.net/wiki/Main_Page
Another cool thing that there is a second progression layer down the road, but I haven't reached it yet. Im eager to see what it brings.
Overall I love the sense of progression, USI can give 3 days of offline rewards, most things are automated and can be played fully afk and the dev is working on the game and pushing updates with extra content, which is always nice. I also heard its coming to the mobile devices and the progress is syncs, so we can always play it a bit on those toilet breaks :D
I highly recommend this game, its a good long term incremental/idle investment in my opinion.