for x-men only 4 players https://forum.recalbox.com/topic/3580/jeux-d-arcade-de-plus-de-2-joueurs?page=1
you need to find clone game xmen6p.zip I think
this game appeared in the romset mame 0.147
http://adb.arcadeitalia.net/dettaglio_mame.php?game_name=xmen6p
but in fba 0.2.97.44
This game is not available
<game name="xmen2pa" cloneof="xmen" romof="xmen">
<description>X-Men (2 Players ver AAA)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-aaa04.10d" size="131072" crc="7f8b27c2"/>
<rom name="065-aaa05.10f" size="131072" crc="841ed636"/>
<rom name="065-a02.9d" merge="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" merge="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" merge="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" merge="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" merge="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" merge="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" merge="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" merge="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" merge="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" merge="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_aaa.nv" size="128" crc="750fd447"/>
</game>
<game name="xmen2pe" cloneof="xmen" romof="xmen">
<description>X-Men (2 Players ver EAA)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-eaa04.10d" size="131072" crc="502861e7"/>
<rom name="065-eaa05.10f" size="131072" crc="ca6071bf"/>
<rom name="065-a02.9d" merge="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" merge="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" merge="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" merge="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" merge="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" merge="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" merge="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" merge="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" merge="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" merge="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_eaa.nv" size="128" crc="1cbcb653"/>
</game>
<game name="xmen2pj" cloneof="xmen" romof="xmen">
<description>X-Men (2 Players ver JAA)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-jaa04.10d" size="131072" crc="66746339"/>
<rom name="065-jaa05.10f" size="131072" crc="1215b706"/>
<rom name="065-a02.9d" merge="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" merge="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" merge="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" merge="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" merge="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" merge="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" merge="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" merge="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" merge="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" merge="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_jaa.nv" size="128" crc="849a9e19"/>
</game>
<game name="xmen2pu" cloneof="xmen" romof="xmen">
<description>X-Men (2 Players ver UAB)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-uab04.10d" size="131072" crc="ff003db1"/>
<rom name="065-uab05.10f" size="131072" crc="4e99a943"/>
<rom name="065-a02.9d" merge="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" merge="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" merge="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" merge="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" merge="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" merge="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" merge="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" merge="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" merge="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" merge="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_uab.nv" size="128" crc="79b76593"/>
</game>
<game name="xmenaa" cloneof="xmen" romof="xmen">
<description>X-Men (4 Players ver ADA)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-ada04.10d" size="131072" crc="b8276624"/>
<rom name="065-ada05.10f" size="131072" crc="c68582ad"/>
<rom name="065-a02.9d" merge="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" merge="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" merge="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" merge="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" merge="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" merge="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" merge="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" merge="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" merge="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" merge="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_ada.nv" size="128" crc="a77a3891"/>
</game>
<game name="xmena" cloneof="xmen" romof="xmen">
<description>X-Men (4 Players ver AEA)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-aea04.10d" size="131072" crc="0e8d2e98"/>
<rom name="065-aea05.10f" size="131072" crc="0b742a4e"/>
<rom name="065-a02.9d" merge="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" merge="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" merge="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" merge="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" merge="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" merge="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" merge="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" merge="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" merge="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" merge="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_aea.nv" size="128" crc="d73d4f20"/>
</game>
<game name="xmene" cloneof="xmen" romof="xmen">
<description>X-Men (4 Players ver EBA)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-eba04.10d" size="131072" crc="3588c5ec"/>
<rom name="065-eba05.10f" size="131072" crc="79ce32f8"/>
<rom name="065-a02.9d" merge="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" merge="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" merge="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" merge="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" merge="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" merge="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" merge="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" merge="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" merge="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" merge="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_eba.nv" size="128" crc="37f8e77a"/>
</game>
<game name="xmenj" cloneof="xmen" romof="xmen">
<description>X-Men (4 Players ver JBA)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-jba04.10d" size="131072" crc="d86cf5eb"/>
<rom name="065-jba05.10f" size="131072" crc="abbc8126"/>
<rom name="065-a02.9d" merge="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" merge="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" merge="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" merge="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" merge="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" merge="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" merge="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" merge="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" merge="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" merge="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_jba.nv" size="128" crc="7439cea7"/>
</game>
<game name="xmen">
<description>X-Men (4 Players ver UBB)</description>
<year>1992</year>
<manufacturer>Konami</manufacturer>
<rom name="065-ubb04.10d" size="131072" crc="f896c93b"/>
<rom name="065-ubb05.10f" size="131072" crc="e02e5d64"/>
<rom name="065-a02.9d" size="262144" crc="b31dc44c"/>
<rom name="065-a03.9f" size="262144" crc="13842fe6"/>
<rom name="065-a01.6f" size="131072" crc="147d3a4d"/>
<rom name="065-a08.15l" size="1048576" crc="6b649aca"/>
<rom name="065-a07.16l" size="1048576" crc="c5dc8fc4"/>
<rom name="065-a09.2h" size="1048576" crc="ea05d52f"/>
<rom name="065-a10.2l" size="1048576" crc="96b91802"/>
<rom name="065-a12.1h" size="1048576" crc="321ed07a"/>
<rom name="065-a11.1l" size="1048576" crc="46da948e"/>
<rom name="065-a06.1f" size="2097152" crc="5adbcee0"/>
<rom name="xmen_ubb.nv" size="128" crc="52f334ba"/>
</game>
