Excellent
I played this game a long time ago and somehow lost track of it because I kept confusing it with Thing Thing. I'm glad I finally found it again!
The graphics are minimalistic but very cute, and the simplicity of everything really makes it feel 'good' to look at it. The animation as well. Most of the in-game objects seem like highly polished placeholders, and for some reason I really like it that way. My only complaint is that on some surfaces which only have on color and nothing on them, you can quickly lose track of how far you've run in one direction, or how far you've fallen from a ledge.
The sound is excellent!! The voice acting is witty and done excellently, the music is really dramatic and high quality, and the sound effects are very satisfying to listen to.
The gameplay is quite complex, but works out well. I love how simple things work out with only a few extra buttons aside from the arrow keys. Certain things such as the ledge mechanism make the game look extra polished, plus stealth games are something that Newgrounds needs a lot more of.
I think the difficulty is balanced pretty well, motivating the player to use stealth, but the thing that really pissed me off was how easy it was to get lost. The up and down arrows are all but useless for looking up and down; it only gives you an extra 50 pixels of difference! Being able to look 400 pixels in any direction might have been a bit better. This is what caused me to miss the platform that lead up to the guard holding the Wind Staff the first time I played this, and it took me way longer than it should have this time around as well. Trying to figure out where every little nook and cranny is makes the game way too hard for the wrong reasons, and makes otherwise exciting gameplay tedious.
Even so, this game still turned out incredibly. I have to say I'm really glad I found it again!