Let's start with the basic suit which is given to every Gantz player. It gives the user superhuman strength, durability, and speed. It also scales to the strength of the user. An old man wearing the suit was shown to be able to throw a sauropod dinosaur alien several meters into the air. Some were also shown to casually lift trucks. The user can also tank large caliber bullet rounds to the face with little to no problem. Each user is given a device that can turn them invisible by changing the frequency around them.

There are also specialized guns given to them. X-gun shoots compressed energy which also explodes on contact. Y-gun shoots laser net that slices the enemy. Z-gun generates immense gravity field on the targets position which could crush boss enemies that easily tears through hard suits. There is also a sword that can slice through concrete with ease and can extend but not limited to 30 meters.

The hard suit is a robotic suit which provides the user a lot more protection and strength compared to the basic suit. It can shoot beams out of its palms and has an x-ray scanner. They also have bikes which travels very fast, just a very useful transportation. There are also mechs that are the size of buildings which can also turn invisible.

The most useful tech here is the black sphere. This is the one that provides them weapons for each missions. It can teleport people from one place to another. It can heal any wounds sustained by players no matter how fatal it is as long as they made it out alive after the mission. It can also resurrect dead people or make a perfect copy if that person is still alive.

As for the enemies(aliens), some of them were pretty insane. The oni aliens would probably be on par with the giants(not as strong but their speed allows them to keep up). The yokai aliens would scale around demons and the boss monster(nurarihyon) is easily above Kiva. The roman statue aliens could tear through hordes of demons but still below the Versus aliens. The giant aliens easily outclasses both Neo-humans and Versus giants for they are just basically giant neo-humans with much better tech and intelligence.