The Moon Lord is a summonable, post-Lunatic Cultist boss that is generally considered the ‘final boss’ of Terraria. Players often lose a sense of progression after defeating him. The game does not offer much in terms of the storyline after that point, but there are some sub-events and modes that you can find more appealing than a second playthrough.
Regarding scalability, the loot from Moon Lord will set you up for many of the strongest weapons available in Terraria. Stronger equipment is essential in Terraria since it grants you stronger stats and enables you to fight tougher bosses.
Most of the bosses in Terraria are easily beatable using post-Moon Lord weapons so that you can perform daring adventures like:
- Create a teleporting maze
- Fight groups of summonable bosses to flaunt your mastery of the game.
- Build a sky tower straight towards outer space and fight against Martians.
- Craft Monoliths and create artificial altars.
The 2D sandbox of Terraria revolves around exploration and adventure, so your to-do list can fill to the brim with a single touch of inspiration.
9. Play Underwater Terraria
You can try submerging an entire Terraria world underwater and finish the game there. This fun idea has gained massive popularity as a challenge recently. Here is how you can achieve a water world in Terraria.
- Grind fishing quests till you find the Bottomless Water Bucket.
- Create a new expert small world and pour water until the sky islands are completely submerged.
- Create a new character and give them a bunch of Gills potions.
- A sponge is banned in this world. Good luck!
8. Ravage an Entire World with the DCU
The DCU is a late-game mount that summons a rideable, flying vehicle. Its ability to mine blocks is unparalleled in Terraria. It can be oddly satisfying and fun to mine with.
You can try deleting an entire world with the Drill Mount! The recipe for making a DCU is also a challenge to gather. Here is the recipe for the Drill Containment Unit:
7. Purify a World
The corruption and crimson biomes are well known for spreading too rapidly. So why don’t you take the time to remove the entire corruption from your world once and for all? Grab a Clentaminatorfrom the Steampunker, load up the solution, and blast all the Corruption away!
6. Defeat the Dungeon Guardian
Defeated all the bosses in Terraria? You surely forgot this one, didn’t you? You can try to devise strategies to kill the Dungeon Guardian in a pre-Skeletron world.
The trick is to kite the huge head constantly. Remember, a single hit can be the end of you, so try your absolute best if you want to clear this one!
5. Acquire Every Weapon
This might seem easy to clear, but some of the rarest weapons in Terraria can only be found with the help of lady luck.
Good luck with trying to acquire the Zenith since the crafting recipe for it is nothing short of insanity. With that said, the effort is well worth it since Terraria houses a lot of unique and interesting weapons with distinct playstyles and animations.
4. Create a Custom Map
Players have begun creating their unique maps for others to enjoy. This adds a fun and unique twist to how Terraria is generally played. The maps can be based on anything you like and enjoy. Here are some cool Custom Map ideas you can implement in Terraria:
- Puzzle Mazes
- Parkour Maps
- The Floor is Lava
- Aquatic Adventures
3. Build Pixel Art in Terraria
Making art is a great way to pass time and helps relieve stress. You can use blocks to build whatever you like. Be it an anime girl or a Pokemon, simply let your creativity run wild and see what you come up with.
A cool way to integrate your art in a pixelated world is to use the walls for shading and adding depth. This can be incorporated into building unique houses as well.
2. Create A Loot Farm with Conveyor Belts 
You can virtually just stand at a place and have all the loot delivered to your doorstep. You can purchase a bunch of conveyor belts from the Steampunker.
These blocks can move players automatically, dropped items, and town NPCs (but not enemies or critters) in their respective directions upon contact.
1. Build Themed Bases
Themed Bases can be a great way to make the world of Terraria your own. Building an epic base and constantly expanding it can be a fun way to pass time.
This is especially fun if you’re doing a class challenge. You can display all the weapons and armor you collect during your playthrough or even make trophies from the enemies you take down.
Terraria’s terrain arrangement options allow artistic players to construct several elaborate structures. The sandbox design of Terraria gives you a lot of creative choices when building monoliths, buildings, or entire theme parks.
The Crafting stations provide a myriad of material and coloration options for building houses, palaces, architectural experiments, and works of sculpture.
With patience and a stroke of luck, you can acquire multiple rarities to create something wild and artistic even after defeating the Moon Lord.
Wandering aimlessly and accidentally summoning the Moon Lord a second time can be fun. But, it can become boring and redundant, so give yourself some goals to work on.