The sysctl option you referenced (
net.ipv4.icmp_echo_ignore_broadcasts) only deals with IPv4 ICMP echo broadcasts. ICMP echo messages are the messages used to implement the "ping" command-line tool. By ignoring broadcasts ICMP echo requests, your machine won't respond when someone tries to ping a broadcast address (such as 255.255.255.255, or, say, 192.168.1.255 on a 192.168.1.0/24 subnet) to find all the hosts on the subnet at the same time.
This particular sysctl option shouldn't have any effect on being able respond to unicast pings sent directly to the unicast IP address of your machine. Also, this option is only for ICMP echo broadcasts, so it shouldn't have any effect on all the other uses of ICMP besides echoes.