So I just completed this recently. Yes, I know, I'm a bit behind the times, but that's just me for ya. I was in for something indie and mind-tickling, and a puzzle platformer with a focus on fluid physics seemed just the thing.
But, having just rounded out the thing, I have kind of mixed feelings.
On the one hand, the fluid dynamics really are a lot of fun, and some of the puzzles are delicious nuts to crack that in several cases can frustrate you for ages until you smack yourself in the forehead and realize the one blatant solution that was staring you in the face the whole time. Or, even better, you can leave something alone and then eventually come back to it when you have some different resources available to you, thus finding an entirely different solution. The variety of fluro seeds and fluid types allows for a wide range of combinations that can be used as tools for your schemes.
On the other hand, the fluid dynamics really are quite... Uhh... Tempermental. Don't expect something to work the way you expected it to, or the way it did work before, or even to work at all. And for a platformer, particularly one that relies on a fair deal of precision and timing in some parts (just a side note: I would have preferred a heavier focus on complex puzzles than on timing, but that's just me), the controls seemed awfully sticky, unresponsive or just plain uncooperative (this may be due to how my machine processes the game though).
Additionally, the storyline was... Odd. Also very, very indie, for what that's supposed to mean. It felt at times as though the plot and the actual game were at odds with one another. You've got a very colorful, bright and fun/funny game wrapped up with a story that's at least attempting to be dark, mysterious, foreboding, and pensive. And the ending really wasn't that great, if you ask me. I saw the meat and bones of it a mile away, but the epilogue/credits sequence afterwards just left me with a definitive "Huh?" feeling.
A few pet peeves of mine include the fluros themselves, and their at times erratic behavior. Like getting to the last leg of escorting a (spoiler alert) dark fluro around some puzzle, then creating a light source between us that would cause him to go into the dark spot I needed him to get to. Instead, he turned around, ran right over the light source, and kamikaze'd himself on my stunned face, forcing me to start the whole damn thing from scratch. Again.
Another would be the unstable and unprecise physics engine, and the heavy reliance on it being stable and precise. Like walking past a difficult puzzle and leaving it for another time, only to see the puzzle spontaneously explode and solve itself without any interaction from me.
Furthermore, the later parts of the game seem a bit tacked-on, which I suppose is understandable. But the entire last section annoyed me because the machinery I had to fix/restart/whatever was effectively impossible to interact with without causing it to smack me in the face a few times as thanks. In addition, the final puzzle and the final-final puzzle were both a bit strange, with the fluros or other game mechanics suddenly changing for the sake of making things easier/simpler. Add to this the bizarre ending, and the fact that many of the previous mechanics and options are forgotten and disused later on in the game, and everything feels just perhaps a little strained.
But by all means, do play this game. It's a fun, alternative romp that can get your brain-gears whirring and your splishy-splashy sense tingling. Just don't let it fool you into expecting more from the later parts of the game than it actually provides.
Also, in regards to the various upgrades you can get... Pretty much the only thing I used consistently was the seed cannon. Oh lordy, how much easier that makes things...