http://konjak.org/images/noitu2_scr00.gifhttp://konjak.org/images/noitu2_scr02.gif
I recently stumbled upon a PC indie game called Noitu Love 2 - Evolution, which is available for only 10$ on the homepage of the designer, Joakim Sandberg. There is also a demo and a lot of other free stuff on his homepage.
konjak.org/section.php?section=noitu2
This game really has everything. Great retro graphics, hilarious bosses, and a unique keyboard/mouse control scheme which just works. It’s a little short, but for replay value you can unlock two other characters with different attacks and harder difficulty.
Check out the trailer here: http://www.youtube.com/watch?v=ysO4YfKM1E0)
If you want to see how it plays, watch this playthrough: http://www.youtube.com/watch?v=d8O5TfA0q3M
I’ve had this for a while, I agree, it’s really pretty amazing. You get a surprise when/if you finish it!
You can play Noitu Love 1 for free but the sequel’s very different, better and worth buying.
http://www.konjak.org/images/noitu_scr01.gifhttp://www.konjak.org/images/noitu_scr03.gif
He also has this little free game that’s a Zelda side scrolling homage with awesome sprite work, Legend of Princess. Only one level but quite a bit of variety with the different items you choose.
http://www.konjak.org/images/princess00.gifhttp://www.konjak.org/images/princess01.gif
Legend of Princess if how I learned about the games of Konjak. It only lasts for 20-30 minutes of gameplay but gives you a lot of fun and if i remember correctly even three or four bosses. This guy just loves to design bosses. 
This looks pretty cool!
(I’m trying to whittle down my collection of unplayed games so I’m not going to start this right now but I’ll keep it in mind.)