To be honest: If I personally wrote gaming software and needed greyscale for this, I probably would use a far bigger screen with a far higher resolution, backlit and colored and with a faster screen refreshing rate, a faster processor with a by far faster code processing by an embedded C compiler instead of a real slow interpreter - in 1 word: a complete different hardware- and software base.
Not meant to be offending, for you personal it's a big success.
But it's maybe a little comparable to my chess for NXT: it will never be a real competitive chess program, and the virtual on-screen board is really poor, but as a model combined with a moving robot arm it was a personal building challenge - not more.
NXC CHESS for NXT: http://www.mindstormsforum.de/viewtopic.php?f=70&t=6790
indispensable for NXC + EV3-C: easy + trouble-free network & remote control for rs485, Xbee, BT, USB!