Preheat the oven to 375°F (190°C).
In a large skillet over medium heat, brown the ground beef.
Add the chopped onion and bell pepper to the skillet, cooking until softened.
Stir in the ketchup, Worcestershire sauce, garlic powder, chili powder, salt, and pepper.
Spread the beef mixture evenly into the bottom of a large casserole dish.
Arrange the tater tots on top of the beef mixture in a single layer.
Sprinkle the shredded cheddar cheese generously over the tater tots.
Cover the casserole dish with aluminum foil and bake for 25 minutes.
Remove the foil and bake for an additional 15-20 minutes, or until the tater tots are golden brown.
Let the casserole sit for 5-10 minutes before serving.