he vistoctk.c código ofuscado, pero ¿cómo puedo empezar a desenmascararlo?

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/time.h>
#include <signal.h>
#define m(b)a=b;z=*a;while(*++a){y=*a;*a=z;z=y;}
#define h(u)G=u<<3;printf("\e[%uq",l[u])
#define c(n,s)case n:s;continue
char x[]="((((((((((((((((((((((",w[]=
"\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b";char r[]={92,124,47},l[]={2,3,1
,0};char*T[]={"  |","  |","%\\|/%"," %%%",""};char d=1,p=40,o=40,k=0,*a,y,z,g=
-1,G,X,**P=&T[4],f=0;unsigned int s=0;void u(int i){int n;printf(
"\233;%uH\233L%c\233;%uH%c\233;%uH%s\23322;%uH@\23323;%uH \n",*x-*w,r[d],*x+*w
,r[d],X,*P,p+=k,o);if(abs(p-x[21])>=w[21])exit(0);if(g!=G){struct itimerval t=
{0,0,0,0};g+=((g<G)<<1)-1;t.it_interval.tv_usec=t.it_value.tv_usec=72000/((g>>
3)+1);setitimer(0,&t,0);f&&printf("\e[10;%u]",g+24);}f&&putchar(7);s+=(9-w[21]
)*((g>>3)+1);o=p;m(x);m(w);(n=rand())&255||--*w||++*w;if(!(**P&&P++||n&7936)){
while(abs((X=rand()%76)-*x+2)-*w<6);++X;P=T;}(n=rand()&31)<3&&(d=n);!d&&--*x<=
*w&&(++*x,++d)||d==2&&++*x+*w>79&&(--*x,--d);signal(i,u);}void e(){signal(14,
SIG_IGN);printf("\e[0q\ecScore: %u\n",s);system("stty echo -cbreak");}int main
(int C,char**V){atexit(e);(C<2||*V[1]!=113)&&(f=(C=*(int*)getenv("TERM"))==(
int)0x756E696C||C==(int)0x6C696E75);srand(getpid());system("stty -echo cbreak"
);h(0);u(14);for(;;)switch(getchar()){case 113:return 0;case 91:case 98:c(44,k
=-1);case 32:case 110:c(46,k=0);case 93:case 109:c(47,k=1);c(49,h(0));c(50,h(1
));c(51,h(2));c(52,h(3));}} 

http://www.ioccc.org/2001/ctk.hint:

This is a game based on an Apple ][ Print Shop Companion easter
egg named 'DRIVER', in which the goal is to drive as fast as
you can down a long twisty highway without running off the
road.  Use ',./', '[ ]', or 'bnm' to go left, straight, and
right respectively. Use '1234' to switch gears. 'q' quits. The
faster you go and the thinner the road is, the more points you
get. Most of the obfuscation is in the nonsensical if statements
among other things. It works best on the Linux console: you
get engine sound (!) and the * Lock keyboard lights tell you
what gear you're in (none lit=4th).  The 'q' argument (no
leading '-') will silence the sound. It won't work on a terminal
smaller than 80x24, but it works fine with more (try it in an
XTerm with the "Unreadable" font and the window maximized
vertically!).