Frankly speaking, it is not worth buying right now. There is too little content to justify buying and playing this over slime rancher 1 at its current price. If you are looking to play this game after playing the first one, I would hold off until a few more content expansions or wait until it goes on sale; and if you are looking at this game without having played the first one, go and play the first one for now.
My biggest hang-up for this game right now are from the slimes. As of now, there are 21 slimes (19 if you do not count two special ones); only 6 are new, and 15 were in the first game. I have no problem with old slimes returning, but the ratio and how they are placed are my problems. Right now there is pretty much only one new slime in each area zone, and the majority of the ones you see are from the first game. This, for me at least, makes the exploration more underwhelming since I barely see any new slimes which is what I bought the game for in the first place. The game blasts you with old slimes with a sprinkle of new, and I don't feel the impact of this being a new game. Hopefully, they continue adding more new ones, but the first few zones as they are now just feel like walking through slime rancher 1.
Instead of slime ranching, it feels like you are mostly resource gathering. There are currently no benefits to actually improving your ranch. Most of your effort spent to get upgrades, or build gadgets comes from harvesting resource nodes. This sucks, because it is not fun at all. There are no direct ways to increase the amount of resources you're getting, which means that what you're doing doesn't feel improved at all from the start of game to the end. Once they add something to the lower the amount of time spent gathering, the game will immediately feel much better since you will be able to put more of your time at the fun stuff.
Currently, there is not much reason to improve your ranch. It is very easy to get all the plorts and money you need even with very few slimes. Once you have even just two of every slime, then you really don't need any more. There is nothing big to spend your money on like the zz club, or is there a reason to collect plorts besides the collecting aspect itself. With no reason to continue taking care of your slimes most of the time, the only thing you have left to do is continue collecting resources, which as stated earlier, is not fun. They need to balance this and give us a reason to actually ranch more, because I should at least be incentivized to take care of my ranch even when I need to do other stuff.
The graphics are overall pretty good, definitely an upgrade from the first game. Nothing groundbreaking, but good style with an improvement in color and lighting over the first game. I feel they could have done more interesting things with the map traversal, but they seem to be improving in this as the added snow zone is much more interesting to walk around than the previous ones.
Overall, the game isn't terrible, but it is missing elements to its game cycle. The content the game is missing ruins the feel of the game later on and it feels abrupt. It is okay for games to have short play-time, but the game is at a cliff-hanger and it feels bad to have it be where it is. Once they patch these holes in the gameplay, then I can recommend buying this game. But until then, this is not worth the price. Best of luck to the devs, I hope you can finish this game strong.
(I will add some more context for my review here. For starters, I do like this game, and enjoy playing it. I cannot recommend this game simply because this game is incomplete, has been in early access for 2 years now, and is priced too high for where it is currently at. You can get slime rancher 1 on sale for $5 and have an all-around more complete experience compared to this game, plus the game has many years of mod support given to it. I like this game, but paying more for a product that already exists and is cheaper is why I cannot recommend this right now. Once they add enough content to justify its price, then I will change my review to positive. Until then, not recommended.)