Fan Casting The Perfect 90's Sci-Fi Movie

From the far reaches of space, a massive army of alien starships arrives to take over the Earth. Cities are crumbling, people run for shelter, and explosions are everywhere! Now it is up to humanity to bring the fight to them! They team up with killer robots, dinosaurs, and other friendly aliens in a gigantic war to save the Earth and the universe while traveling in space to find the evil alien home planet where their time-traveling device will send them back to prevent all of this from happening once and for all!