I've put about 13 hours into it at this point, and I'd say that it's definitely worth it at the current sale price. It's obviously a work in progress so there are things that are in flux and there are tweak issues (finding particular types of elements), and what feels like a memory leak (not confirmed yet...the last hour was getting laggy and warping, but the twelve previous hours ran perfectly).
I admit I was slightly cautious about picking the game up for months because the art seemed a bit "fuzzy" (not as crisp as some of the other similar games), but didn't seem that way when playing...maybe it was an impression I got from early gameplay videos.
Gameplay is close enough to Terraria that you won't be totally lost; though there are a lot more items to craft and there's more of everything. The variety of weapons and the distinction of the armor, etc, are a plus.
The world is alien and more broken up than Terraria...morea bunch of floating islands, some of which are quite large. I haven't played it enough to distinguish layers and there is some environmental damage mechanic which resulted in the odd death when going to far down but is still a bit mysterious in its workings.
Monsters and combat are more complex and interesting. One thing I find interesting is that somethings are neutral under certain conditions and then hostile in others (sleep mode?). You will often be in a situation where you have to decide how you will engage because indiscriminate shooting may aggro otherwise neutral beasts or plants that will jump in your combat and make your day really bad.
There is a bit of silliness, but so far the majority of the game plays pretty straight...just had the occasional polar bear with jet boots thing but otherwise seems staple scifi.
So yes, I would recommend if you like this type of sandbox game and are willing to do your own research rather than have everything spoonfed in one guide.
<Note: Reservations below are describing the current gameplay experience I am having. They are just things to note and may be addressed tommorow for all I know. On the whole, I am enjoying the game and look forward to seeing it get the polish that will really make it shine.>
My main reservation is that, especially in such a "complex" type game with many concepts and crafting being such a main component, that documentation is sparse. Of course documentation is one of the last things put in a game but even the community is really light in consolidated guides (at least in English...there are other language guides that may be more fleshed out). This isn't a reason to not pick up the game but it will get a lot easier to play when you don't need to troll forums for basic game info (ie: what are dungeons, what do you need to go there) or how do you upgrade weapons.
Other more minor reservations include "Hmmm, I build this item and put it in my base...just what does it do again? Perhaps pop up tooltips for placed crafting stations or maybe an intergrated icon to jog the memory.
Ladders, or other ways to go UP besides jump packs.
Some sort of ablative heat shield/air bag for when you jump into an abyss that is many screens deep.
In the crafting menu, have another grouping "misc" for all items that don't fit under weapons or base items or any of the other crafting subgroupings, so that when you want to craft something you don't need to scroll through the "all" category to find it.
An interface to show you what items you can make in list form all on the screen at once (and the ability to hide items that are outdated). Sort of a tech tree at a glance.
The ability to choose how long info stays on screen before disappearing, and the ability to configure what is displayed. IE: I don't need to know xp as it accrues, but I would like to know when I ding a level in crafting what new recipies I had without looking through the browser.
I assume XP bar fills and you get no more? If so, maybe some sort of on-screen alert so you know to burn that XP instead of wasting time doing things with a full bar.