If any of you are willing to play a higher difficulty and run through the story one more time, I highly suggest that New Game+ as a first option towards the end of the game. First things first, when you start New Game+, you will lose all of your main quest related items and all side quests will be restarted once again. However, you do keep the same loot, player progression and customizations made to yourself just before starting New Game+. And before any of you start to worry about New Game+ being easy for all the progressions you made, please also know that New Game+ has an algorithm that determines the most neutral difficulty multiplier based on the loot and builds you have on your character so the game feels like a new breath of challenge every time you start the game.

For example, If your character is Level 70 with Exotic Apocalypse Tires, the lowest you can expect the multiplier to be once NG+ is started is around 3.5x. (WOW!) NG+ tries to make the game at a level that which even level 90 players have a tough time playing so that the game's difficulty almost feels untouched no matter what level you're at.

Please keep in mind that the difficulty multiplier is determined by the loot you have EQUIPPED on your character since your last save!

If you had equipped low level gear from your last save whether it be Manual or Autosaved, the difficulty will adjust accordingly to that alone! Make sure its a first priority that you equip the gear you want to start the game out as before starting NG+ just so you avoid the game being pathetically easy whenever you do pick up better armor quick. Because also remember that loot drop chances remain the same because of the overall base level your character is at!

The moment you complete the story of the game, its notified just after finishing the game credits that a new dungeon was opened up and Putt-Putt was given a key to access the dungeon. This is a new dungeon added since Update 1.04. It's a procedurally generated dungeon found in the swamp section of the Forest of Once at the very center of the lake. It's a 100 level dungeon with procedurally generated floors that progresively get VERY difficult as you ascend its floors (And I mean PUNISHINGLY difficult). However just like New Game+, this dungeon also uses a difficulty multiplier adjusted seamlessly based on the gear you enter with, and the gear you collect and use along the way.

There are a ton of things that must be acknowledged upon entering Handbrake Tower:

1. You cannot save no matter what, and all progress is lost if you leave.
2. Any gear you find will not be kept until after you've beaten all 100 floors.
3. It costs a small fee of coins that increase by 1.5% each time you want to attempt them again. (The fee percentage is increased by 1% each NG+. The starting amount is always 200. Always have your wallet ready before you start!)
4. You cannot pause the game and Rings are removed during the entire span of the dungeon. You cannot enter with any rings, however, casting spells can be done to go around this. If you go through your menu and inventory during the dungeon, be EXTRA careful! Health is vital in Handbrake Tower!
5. It's only Putt-Putt, no pets or allies during the dungeon.

Once you got that all down, swim to the tower, and enter the lobby floor, Floor 0. Here, will be four Skeletons behind counters that you can buy weapons, armor, refill your health and save in the lobby, and a skeleton that begins the dungeon itself. Don't worry though, your gear will NOT break once you enter the first floor so durability of all gear is ensured upon starting. Be sure to always make defense a priority, and avoid getting hit at almost any cost. You're by yourself so no parties can join you, and you get only one shot to go through all 100 floors without dying. Always use the most out of safe rooms when you run into one and all floors in the order that what comes inside each one is random. These are the rooms you will find in no particular order.

-Mazes (With or without enemies. Usually ones without enemies are much longer and deep. May also contain traps, dangerous platforming and a ton of claustrophobia! Make sure the camera doesn't get stuck.)
-Boss Rooms (Contains only overworld bosses, no story specific ones. All bosses have default level.)
-Enemy Arenas (Can throw almost any basic enemy at you and will have the same level as your character no matter what which sometimes, admittedly, can be ♥♥♥♥♥♥♥♥ if you're unlucky.)
-Platforming Rooms (My personal favorite, contains enemies at random places and usually puzzles.)
-Branching Path Rooms (These ones you get to choose which other room you'd like to do instead. You only get two options of rooms and will never require you to do both of them, nor will both options be the same thing.
-Safe Rooms (Contains a high level bed to boost stats, and a skeleton sitting near a fire who will trade random items with you. You can only trade items you found only from running the Tower.)

Lastly, don't forget to have as much health as you can before you start! This is important as if you don't remember to visit the skeleton behind the counter and start without full health and condition, you start the tower as is! Good luck!

For more casual players looking to distract themselves with side lore and characters, joining Guilds and certain Factions can provide a questline to do upon entering. Keep in mind, don't confuse Factions and Guilds with Covenants which will not have Story Lines at all and only provide stat boosts instead. Covenants and actual Factions can be easily distinguished between the two once you talk to its leader and be given the option to join.
Here's a list of Guilds and Factions you can join all with their own questlines and rivalries. On another note, keep in mind that rival guilds and factions are ones you cannot join once you're in the other.

Here are some Factions with rivalries:

-Project D: Rivaled with Any Group behind the law and Truck Freaks (You'll be considered an outlaw joining Project D so you're always wanted)
-Truck Freaks: Rivaled with Project D and Exotic Autos
-Exotic Autos: Rivaled with Truck Freaks
-Dragon Club: Rivaled with Highway Patrol (Also always wanted)

Here are also some Factions without rivalries:

-Ceaseless Discharge
-bp gas station
Big Bell Hells

If throughout the course of the game, you never gotten yourself married to any character, or never got the item required to do so, get yourself engaged to that one Loli character in the game against his/her own will. (A he if you fell for a trap. Yep, there are trap loli characters in this game.)

1. Head to Uganda, and buy a diamond necklace from the magic shop.
2. Talk to any NPC and ask them to marry you.

Any NPC can easily be married as long as the character is adult and you've talked to them at LEAST once. If you've never talked to an NPC and try to do it, they will say no, but wait a day later and they will say yes. It just works. And no matter what gender or race you or they are, they can be married. Now him/her can move into a house you own together and depending on who that NPC is, can either open a shop and bring in a share of money she earns from the store, or come with you as an ally if she's more of a combat NPC. You can tell between ally NPCs and regular store NPCs based on the gear they wear.

You cannot divorce someone you've married. It's a permanent decision.

And yes, you can marry a motorcycle and even an animal from the Zoo.

If all of the previous methods have been exhausted, the last thing you can do is wait for expansions. Sure there may be other expansions and other games already released like Putt-Putt Goes to the Moon or Putt-Putt Joins the Parade but if anything, for the sake of the future of the franchise, wait patiently for the new games to come out like Putt-Putt Travels Through Time. Who knows what the future of the franchise could hold? We'll just have to wait and see.