Achievements are unexplained tasks that you can complete in-game that often unlock new objects to use in your park once the requirements are completed.
Please note that no tasks other than Getting Started have been confirmed by the developer, meaning tasks and completion suggestions may be generally incorrect. Most of them have been tested for clarity though some tasks have a wide range on how to complete them and therefore testing is unclear. If something is incorrect, you can change it.(I cannot edit the exact area, but the 'Nice and Tidy achievement is only unlockable with at least 100 guests in the park. I completed it with 12 trash cans.)
Task: Complete the tutorial and gain 5 visitors.
Reward: Steel coaster
The park is growing!
Task: Get 2 Stars on your park.
Reward: Inverted coaster
Nice theme park!
Task: Get 3 and a half stars on your park.
Incredible theme park!
Task: Get 5 stars on your park.
Task: Add water to your park.
Reward: Log flume
Task: Have five hours of total playtime.
Task: Create a Transport train with at least three stations, and each station has an entrance and exit.
Completion suggestion: Ensure all the stations have the same amount of station tracks. A minimum of three is needed.
Task: Ask a player to add you as a Co-builder (through the settings), then place or remove anything in their park or change the status of a ride.
Task: Get ten likes on your park.
Reward: Shiny thumbs up
Task: Build a roller coaster [mostly] in the advanced coaster builder, then open the ride with an entrance and an exit. Remember to let the ride go through at least once, either through testing or open settings, to get credit.
Completion suggestion: Try using ALL basic track elements (chainlift, boosters [if available], and brakes) correctly for the most effective result.
Reward: Spinning coaster
Task: Get $100000 through any means possible (gaining it yourself, or purchasing it from the store).
A worthy park!
Task: Make your park worth $200,000+ (unconfirmed)
Completion suggestion: Place expensive rides such as Enterprise, Fireball and Ferris wheel. Placing multiple expensive coasters with long track lengths also helps. You can also place many personal statues or mannequins to get the achievement quickly but if not placed on the right places, they could be a bad investment.
Reward: Launched freefall
Nice and tidy!
Task: Place, at minimum, 25 (value unconfirmed) trash cans in your park, and have no trash in your park, at the same time.
The big picture!
Task: Line up 9 square borderless image panels in a 3x3 square and add images to them.
Completion suggestion: Try using different decals for each one.
Reward: Hanging flag
Spin to win?!
Task: Create a spinning coaster that has a maximum spinning speed of 360+deg/s. Remember to let the ride go through at least once, either through testing or open settings, to get credit. There must also be an entrance and exit on the ride. Note: You need to unlock the achievement "Promode!" before starting this one due to it using the spinning coaster.
Completion suggestion: Try creating a coaster that reaches the default height limit, then drops down using wide spiral down pieces ("More pieces" menu) to create a helix. Lower a large section of terrain for more spiral pieces. This is a basic design that can help with attaining higher spinning speeds. It may also help if the track is banked at certain areas.
Explore the world with swans!
Task: Create a swan boat ride that goes around the perimeter of your park (1 block in). This requires you to have all park sections unlocked.
Completion Suggestion: Build the ride underground, as to not cut off your park (and income).
Reward: Water alterator
Task: Place four fire ball rides in a tower chain pattern.
Completion suggestion: Start with a fire ball ride on the ground. Take fire ball 2 and rotate it 90 degrees, and put it aligned in the middle of the first one, with the bottom part of 2 as close to the top part of 1. Take fire ball 3, turned 90 from 2, and align it the same way. Do the same for 4. The rides do not need to be running for credit. The achievement is not possible if started at the default height limit without the height limit gamepass. Dig deeper to begin building.
Reward: Light orb
Mega duck invasion!
Task: Place 35 (value unconfirmed) mega ducks in a short amount of time in a pond.
Completion suggestion: Own at least $20,000 in game. Create a 6x6 pond. Start placing ducks as fast as you can. It is much easier to do this with at least 2 players. All players involved will get the acheievement.
For the extreme children!
Task: Create a junior coaster that has a high intensity rating (value unconfirmed).
Completion suggestion: Beginning the coaster at the lowest possible height and building it up as high as possible and then going down is a good way to increase speed, which can increase the intensity rating. Using complex part pieces from the advanced editor or pieces from the special pieces section, if used correctly, can increase nausea and therefore increase intensity. Both the Ride operations gamepass and/or the Increased height limit gamepass can assist in this achievement's completion as they can allow higher speeds to be achieved, along with more complexity.
Task: With at least 80 visitors in you park, prevent any of them being able to leave by blocking or deleting all paths to the exit. Achievement awarded when all current visitors in your park want to leave your park.
Completion suggestion: Closing your park speeds the process up, and you can try closing some rides and increasing prices of stalls to drop visitor's interests. Deleting the single path in front of the exit will trap all current visitors in the park.
Task: Kill ten visitors at once.
Completion suggestion: Visitors can be killed by making a custom track ride that does not end at a properly placed station. The custom track ride must be able to have ten seats running at the same time, meaning that the coaster must be a Steel Coaster, Phase-turbine Coaster, Inverted Coaster, or Multi-launch Coaster.
To allow ten visitors to sit into the queue, consider making a free steel coaster with 8 station segments that takes around 240-300 seconds to complete a loop while all other rides are closed.
One can also use smaller coasters by using an entrance blocking bug; place a hedge or other fence blocking the entrance on the entrance block while the ride is open and the ride will register with a queue but visitors will not be able to enter. If it is placed on the queue path, the ride will register without a queue and visitors will leave. Once there are 10 visitors in line, delete the fence and they can enter.
To the moon!
Task: Create a multi-launch coaster that launches a car vertically upwards on a 90° incline (of which does not end) with a speed of least 215km/h. The coaster then needs to be run through at least once and the cart must break.
Completion suggestion: Achieve high speeds with boosters. A 90° incline is achieved by using the smallest "up" piece, then the second "up" piece, and then the vertical "up" piece. The cart must break in order to get the achievement.