For gameplay info, go to Emperor Fossil's Details.
Queen Fossil starts off the same regardless of the zone you choose, where you start off by firing at this cannon on her tail that begins to spray, in a somewhat unusual spread pattern, arcs of straight lasers. There very often is a very visible gap for you to plunge through to avoid being hit. There are also destructible missiles to bother about, but they shouldn't really be a problem. Do your best to destroy the cannon now, as blowing it up nets you a red power up.
Now your route will choose which part of Queen Fossil you attack.
Choosing Area E will take you topside. Queen moves out of focus and then turns her back to you. Three cannons, the first and third of which fire orange shots, now greet you, but even with the three enemy formations coming at you before these cannons start firing, you can easily destroy them if you start your attack as soon as possible. Grab the purple power up from that third formation when the cannons are destroyed. A couple more formations will come at you as Queen readies and lets her back set of razor fins fly out to the background before they come back and enter your attack plane. Blowing up the third one will get you a green power up, but be careful. She sweeps out again and some more missiles come at you, then you move further along her back. Here you've got the same cannons below you, only they all fire blue destructible shots. There is also a gatling cannon in front of you that fires a vigorous set of orange bullets and three straight laser cannons above that, which will each fire a 90º angling shot every now and then. Concentrate on these first, and then the gatling cannon for a blue powerup. The other set of fins fly out, and this time the third one holds a red power up. More missiles fly out and she rolls onto her back. Below her head, a hatch by her neck opens and some Orange Shield Things bother you along with other small enemies, two of which give a red and a purple power up. Lastly is a newer version of the captain, Queen's Child. Make sure to capture him for the firepower and cover.Queen Fossil takes the plunge after emerging, and strictly speaking, this is when the actual 'boss' confrontation begins. She charges you head-first now from the left after a warning tells you to get to the right side of the screen. She fires big Solidnite shells that are destructible, but note that they absorb Alpha Beams. She comes in and shows you her left side. Some of her scales fly off and spin around her as straight lasers fire out in a sweeping arc pattern. Eventually that stops as the scales come in a circle and then charge you. Then she opens up her side and Orange Shield Things come out along with projecting four cannons. If you have lost Queen's Child, then capture an OST, immediately absorb it, and then fire your Alpha Beam. This is your only chance on this bottommost route to do a Quadruple Counter Alpha Beam, which gets you a full one million points by itself, and Queen will not survive. TAKE NOTE: if you HAVE Queen's Child, absorb it but DO NOT fire your Counter Alpha Beam at the first Beta Beam, because the fourth and final Beta Beam will hold back your Quadruple Counter Alpha Beam for almost its entire remaining length and you risk not being able to destroy Queen Fossil with it.
If you mess up on this, Queen Fossil presents her tail to you and fires lasers (if the cannon is still there) or bullet arcs as the tips of the tail try to fire lightning at you before she goes off-screen. She angles into the background and fires missiles to the top and bottom while she heads off to the right. Look below to Area F for the pattern to expect next.
Choosing Area F will takes you to Queen Fossil’s underside, and there are more power ups overall to be had from this route. An arm will pivot down and open up to spray blue, destructible bullets at you. Destroying it will spawn both a red and a purple power up. Then as Queen swings out to the background, she rolls and releases small formations of enemies that will show up from either side of the screen; the very first formation has an enemy with a blue power up for your Arm shielding. You also get a red power up from the second-to-last formation. When this is done and she comes back to the attack plane, this is a good time to charge up an Alpha Beam if you have a capture.
Queen Fossil will turn and angle straight down and release two containers with turrets that fire three-bullet streams and which fire missiles between them as they stagger back and forth. They take a lot of firepower to destroy, so using an Alpha Beam is the best method to destroy them, whereupon the top container gives you a purple power up and the bottom container gives you a green power up. When they are either destroyed OR fly off, get away from the top half of the screen as Queen will come down all of a sudden after the alarm stops. A hatch opens on her underside more towards the front and a red laser cannon comes down into sight. Carefully be above it and as Queen bobs up and down, pelt that cannon with lasers and bombs until it is destroyed and you get another blue power up. Orange Shield Things and other little enemies drop and then comes a new Queen’s Child. Blow off its protective armor and capture it. Get all the way over to the left side of the screen.
Queen takes the plunge into the clouds after emerging, and strictly speaking, this is when the actual 'boss' confrontation begins. She will charge you head-first from the right. She presents her left side to you, opens it and extends four long laser cannons, with two gray ones on the ends that fire continuous lasers and two red ones in between them that will intermittently fire a few lasers in succession. During this attack, small destructible bulbous missiles will come after you. When the attack ends, orange diamond shot spreads will fire in three triple bursts. Use Queen’s Child as a shield if need be or stop before it is absorbed to keep it from getting too damaged if you're good at dodging. Then comes a volley of straight, destructible missiles. Queen then presents her tail and fires lasers (if the cannon is still there) or bullet arcs as the tips of the tail try to fire lightning at you before she goes off-screen.
She angles into the background and fires missiles to the top and bottom while she heads off to the left. Dodge them as you get to the right side of the screen when she charges and destroy or dodge the big Solidnite shells with your main laser weapon. Queen will present her left side again but with her head pointed towards the screen (out of view) and release eight scales that form a flower to protect her from your shots as orange diamond bullet arcs fire at you in succession. Eventually, that scale flower will fly right at you, so move out of the way at the right time.
Then Queen opens her side as Orange Shield Thing enemies come out and two lines of orange diamond bullets fire, and this will happen three times. Make sure to grab a capture if you’ve lost Queen’s Child, OR absorb it as this pattern starts and dodge the diamond bullets. Queen will turn and point her tail at you, and as staggered diamond bullet arcs fire, which you can stay in one place and avoid being hit, she charges a full Counter Beta Beam and fires it. Release your Alpha Beam and overtake it, and this should kill Queen Fossil. If you lost your capture, be careful as the multicolored curving homing lasers will first fire from the top and then the bottom of the tail and come after you with little room for you to dodge due to the Beta Beam.
From this point, Queen angles to the background, releases the missiles from the top and bottom, and the pattern will repeat from the charge from the right until she either self-destructs or is defeated.
Queen Fossil is the 2nd boss that plays the 2nd theme (B.T. Dutch).