Bus Passenger Sort is a captivating and challenging puzzle game that falls under the "color sorting" or "match-3" genre, often adapted for mobile platforms. While "Bus Passenger Sort" itself functions as a descriptive term rather than a single official title, several popular games closely match the described mechanics. The most prominent examples include "Bus Jam Sort: Match Passengers" and various iterations of "Bus Stop Jam."

Core Gameplay Mechanics and Objectives
The primary objective across these games is consistent: sort passengers by color to match them with their corresponding bus. Players encounter a line of passengers, each assigned a specific color (green, red, blue, etc.). Buses arrive, also displaying a distinct color. The goal is to move passengers from the waiting line onto the bus of the same color.

The challenge intensifies due to crucial constraints, as highlighted in your description:

Limited Waiting Line/Overflow: A key mechanic is the restriction on how many non-matching passengers can be held temporarily.
In games like "Bus Stop Jam Game" (web version), players are explicitly given a limited number of "extra seats" (e.g., 5) for temporary passenger overflow. Each bus typically has a capacity (e.g., 3 passengers), and once filled, a new bus arrives.
"Bus Jam Sort: Match Passengers" employs a similar concept with "empty tiles" where non-matching passengers wait. The critical rule is that if the bus and passenger colors don't match, there must be available "empty tiles" for the passenger to wait. Failure occurs if there are no empty tiles (or waiting slots) left, and a non-matching passenger cannot be placed. This directly corresponds to the "waiting line is full and you fail to place the right passengers, you lose the game" rule you mentioned.
Strategic Placement: Players must strategically decide which passengers to move and when, anticipating upcoming bus colors to prevent the waiting line from overflowing.
Increasing Difficulty: As players progress, levels often introduce more colors, a faster pace, special passengers with unique requirements, or more complex arrangements, demanding quicker decision-making and more foresight.