If you want to speedrun Metroid Dread, then you need to do some sequence breaking. This refers to any time you get an item earlier than usual. A lot of these shortcuts are baked right into the game – early Morph Ball Bombs can be used to insta-kill Kraid, for example. The Cross Bomb ability is another one you can reach pretty quickly if you’re up to the challenge.
Step one, you’ll need Ice Missiles, and it’s possible to get them early too. Once you do that, exit the EMMI Zone through the top-right door, hop up to the ledge, and use your new Ice Missiles to kill the fiery Enky in the way – there’s an Energy Tank right on the other side of it, too. Now continue up this path through the Grapple Beam Door, and head to the bottom-left corner of the next room. You’ll fall through some Pitfall Blocks into a cave containing the Pulse Radar.
Using that, you can find the exit and leave this room by deploying a few Bombs. Follow these snaking tunnels down, and we’ll finally arrive at the important spot. It’s shown in the screenshot below if you need to verify your location.
The bottom-left square is a Beam Block, which you can Bomb through. Head into the next room and stop by the Energy Recharge Station. From here, we’re going to start running to the right with the Speed Booster. You’ll be able to stop and charge up a Shinespark just as you reach the wall. This next part is a bit tricky. First, shoot the Beam Block to clear your way, then jump back into the tunnel above – if you jump at an angle and spin, Samus won’t actually use up the Shinespark. Now quickly roll over and deploy a Bomb to clear that block, then Shinespark to the right. You can start to release the Shinespark before the Bomb detonates if you time it right.
This launch is enough to get you through the sloping tunnel ahead (picking up a Missile Tank on the way) and out the other side. The hardest part is done. In this tall chamber, you want to exit through the Grapple Beam Door at the bottom left. Then give yourself enough runway to Speed Boost back through it and Shinespark straight up the right side of the cavern.
Head through the door up there and follow the tunnel to reach the Golzuna boss fight. The monster may be slightly tougher to take down at this stage, but it’s totally doable. Once you win, you’ll steal its Cross Bomb ability much earlier than Dread would normally let you have it.
You might think you’re stuck at this point due to the Screw Attack Blocks above the Golzuna boss room, but you’re not. Return to the tall chamber from before, but this time shoot yourself up the left side. On your way back down, you can catch the ledge of the tunnel where the Missile Tank previously was. That’s your way back to the game’s main path – unless you want the early Gravity Suit too.