First, I want to say that I understand that this is a game developed by a single person, I think it has some promise, and I absolutely support developers learning the ropes and trying to make it. So despite the fact that I can't recommend the game, I applaud the developer for his effort.
The game is a Super Mario 64 / Super Mario 3D Land style 3D platformer where the world is made up of a bunch of connected geometric objects. You're a tree. You can run, jump, swing a leaf to attack... and that's about it. The objective of each level is to get three water drops and get to the end of the level; there are also berries scattered around (around 100 berries per level or so). You don't need to collect berries to finish the game, but if you collect 200, 400, or 800 you can "upgrade" your leaf, at 850 you get a headband for your character which seems mostly cosmetic, and there's an optional hidden level at 600 berries. There are 6 main game levels plus the optional level. Each level takes about 8-10 minutes. Personally I 100%ed the game--that is to say beat all levels and unlocked all optional content or unlocks in-game--at 71 minutes.
The issue is that much of the core gameplay loop doesn't work very well. Your default walk speed is far too slow, your default run speed is far too fast to be controlled for precise jumps. The game also never tells you you can run, so, PRO-TIP: You can. Underwater, everything is too slow and the physics don't adjust at all besides movement speed. Jumping is not controlled very well and I frequently missed pretty easy jumps. There are clipping issues. There are almost-but-not-quite making a jump and getting stuck in the lip of geometry and having to jump again to get unstuck issues. There are also issues where you feel like you've picked up a berry but you aren't inside its hitbox, so you sort of wander back and forth until you pick it up. You almost never get good feedback--the "feel" of the game is a real problem.
When you die (you will, frequently, enemies AI is basic, many enemies are stationary, the rest move in fixed patterns, but clipping is generally poor and it's difficult to tell if you're going to hit an enemy when you swing your weapon), you respawn instantly either at the beginning of the level or at a checkpoint, but you can't see where the checkpoints are and in my experience they're rarely where they make sense to be; but because enemies and items don't respawn when you die, you basically run through an empty level until you get back to where you died.
The camera is the biggest problem. The camera angle is frequently no good; for example, in a 3D platformer the camera should never be directly on your level facing straight, because it ruins depth perception entirely. The camera should never be so close that it obscures the action, and yet it is. Worse, as you collect berries, the bag your character holds gets bigger and bigger, so the obstruction is actually worse at the end of levels than at the beginning. You should never have to run towards the camera and take leap-of-faith jumps to get to platforms unless there's some visual indication that you ought to.
It's an hour long game, so obviously if you want to play it, you'll deal with the frustration. But it's pretty rare that you're playing and something isn't going to be bugging you.
The music's composition is not bad (it is a little simple, and it's not really catchy), but the author chooses very very very chintzy, cheap sounding samples for almost every instrument. In particular there's some sort of harpsichord used as one of the main instruments and it sounds really terrible. Sound effects are rare, to the point that the game feels a little unfinished because there are times where you expect sounds and don't get them.
You can't quit the game from inside the game without doing an Alt+F4 or Apple+Q or whatever. There's no main menu to go back to. When you beat the game, it sits at the end of the credits section. This is very frustrating to me. There's also no Steam Cloud support, and although the game is multi-platform, achievements don't work on the Mac or Linux versions.
It's a pity because the graphic side of things is very good. The enemies and your character are cute. The visual style is simple but colourful, and reminds me favourably of Mario 64 or Super Mario 3d Land. There are lots of little touches in the animation. If I had to guess, the guy is probably an animator or an artist who made a game, rather than a programmer.
I don't want to dissuade the guy from continuing to make games and there are occasional hints of promise, but it comes off more as the kind of thing that would have been free online in the late 90s / early 00s, or the kind of thing that would be released on Desura. I am confident that before Steam changed the approval process to be more open last year, this game would not have seen release. Moreover, the dev is still actively patching the game, but a lot of what he's adding in seems to be stuff that would be typical of a 1.0 release, which makes it seem even more like a hobby project.
It's definitely an earnest effort and I hope the dev keeps trying, but I don't think it's /there/ and besides supporting the dev, I don't really feel like there's much to recommend here.