I see everyone votes for a game not for the retro-ness but for how complicated it must be to create the game?

I liked space invaders 1989 a lot! It felt ancient, really well made.
Castle wolfendoom was a great one as well, reminds me very well of the days I was playing the real one .
Golder slash was a good reïncarnation of good 'ol boulder dash, I enjoyed it a lot.

Most of the others were great submissions, but not all of them worked fine for me or were fun but didn't add something extra to give a retro feeling.

MM3D was very slow, couldn't play it well and it didn't felt very retro.
In Golden Eye I kept clicking outside the window and defocussing the game all the time. Though it is an old game, it doesn't quite qualify as retro for me.

I'll admit I have voted for my own, not for the win but because for me it gives the most retro feel that the other games didn't give. Well it was a very close call with space invaders 1989.