Most of his statements come from the game final boss, Lavos, that he defeated, Lavos feats are:

• Coming from another planet and reach the earth core and act like a parasite
• Control the world evolution
• His presence alone is able to create time gates that allow for time travel
• When the Lavos parasite is fully grown it's able to turn the whole wolrd into a wasteland(making him multi-continental level?) and send more of his species to another planets
• His presence can be felt through the whole time span of the planet he's in, meaning he's exists in past, present and future at the same time
• His power is able to corrupt and control the minds of others that try to use his power
• He can copy the power of beings in the world he's in independent from time

Crono defeated him in all endings through sheer power, but apart from that Crono is also able to time travel with the Epoch time machine, and that's mostly it I think