Guessing game between the range(1..1000)

game.rb

actual_number = rand(0..1000)
puts "Can you guess the number I am thinking?"
print "It is between 0 and 1000: " 
guess = 0 

def invalid?(user_input)
  !!user_input.to_s.match(/\A\d+\z/)
end

while actual_number != (guess) 
  guess = gets.chomp
  if invalid?(guess) == true 
    if guess.to_i == actual_number
      puts "Congratulations, you\'ve guessed the number"
      break
    elsif guess.to_i > actual_number
      puts "Too high, try again..."
    else
      puts "Too low, try again..." 
    end
  else 
    puts "Number only please"
  end
  print "Try again =>"
end

If you try to enter anything besides number it will tell you to "number only." You must only put numbers in.