If you get bored of evolving zerobots, you may try this one (or a variation of it) with mutations disabled.
cond
*990 0 =
start
998 rnd 530 rnd 2 div abs 1 add 971 store
998 rnd 530 rnd 2 div abs 1 add 972 store
998 rnd 530 rnd 2 div abs 1 add 973 store
998 rnd 530 rnd 2 div abs 1 add 974 store
998 rnd 530 rnd 2 div abs 1 add 975 store
998 rnd 530 rnd 2 div abs 1 add 976 store
998 rnd 530 rnd 2 div abs 1 add 977 store
998 rnd 530 rnd 2 div abs 1 add 978 store
998 rnd 530 rnd 2 div abs 1 add 979 store
998 rnd 530 rnd 2 div abs 1 add 980 store
998 rnd 530 rnd 2 div abs 1 add 981 store
998 rnd 530 rnd 2 div abs 1 add 982 store
998 rnd 530 rnd 2 div abs 1 add 983 store
998 rnd 530 rnd 2 div abs 1 add 984 store
998 rnd 530 rnd 2 div abs 1 add 985 store
998 rnd 530 rnd 2 div abs 1 add 986 store
998 rnd 530 rnd 2 div abs 1 add 987 store
998 rnd 530 rnd 2 div abs 1 add 988 store
998 rnd 530 rnd 2 div abs 1 add 989 store
998 rnd 530 rnd 2 div abs 1 add 990 store
*.thisgene .delgene store
stop
cond
1000 *.kills 1 add mult rnd 5 =
start
971 19 rnd add inc 999 ceil store
stop
cond
1000 *.kills 1 add mult rnd 10 =
start
971 19 rnd add dec -6 floor store
stop
cond
*.fixed 1 =
start
0 .fixpos store
stop
cond *971 *972 * > start *973 *974 * store stop
cond *971 *972 * = start *974 *975 * store stop
cond *971 *972 * < start *975 *976 * store stop
cond *973 *974 * > start *973 *974 * store stop
cond *973 *974 * = start *974 *975 * store stop
cond *973 *974 * < start *975 *976 * store stop
cond *975 *976 * < start *977 *978 * store stop
cond *975 *976 * > start *978 *979 * store stop
cond *975 *976 * = start *979 *980 * store stop
cond *977 *978 * < start *977 *978 * store stop
cond *977 *978 * > start *978 *979 * store stop
cond *977 *978 * = start *979 *980 * store stop
cond *979 *980 * < start *981 *982 * store stop
cond *979 *980 * = start *982 *983 * store stop
cond *979 *980 * > start *983 *984 * store stop
cond *981 *982 * < start *981 *982 * store stop
cond *981 *982 * = start *982 *983 * store stop
cond *981 *982 * > start *983 *984 * store stop
cond *983 *984 * = start *985 *986 * store stop
cond *983 *984 * < start *986 *987 * store stop
cond *983 *984 * > start *987 *988 * store stop
cond *985 *986 * = start *985 *986 * store stop
cond *985 *986 * < start *986 *987 * store stop
cond *985 *986 * > start *987 *988 * store stop
cond *987 *988 * > start *989 *990 * store stop
cond *987 *988 * = start *990 *971 * store stop
cond *987 *988 * < start *971 *972 * store stop
cond *989 *990 * < start *977 *978 * store stop
cond *989 *990 * > start *978 *979 * store stop
cond *989 *990 * = start *979 *980 * store stop
end