You have a few options, mostly achievement related
High on Life is so packed with jokes, that much the game itself could be considered “postgame/endgame content.” You’ll likely miss a lot on your first run, so barring another playthrough, there’s a lot you can get done in the postgame after clearing the final boss. Here’s a comprehensive list.
Get all of the Luglox chests in each area
If you’re looking to go for a 100% clear, Luglox chests might be the last thing you do (note that they are also linked to an achievement).
High on Life thankfully straight up tells you how many chests you have remaining in each zone. You can hunt for them, clear them all out, and move on without feeling like you’re on a wild goose chase.
Get every upgrade in the game
With all the cash you’ll be earning from those chests, you’ll be able to buy more upgrades at the pawn shop in Blim City.
Consider aiming for the jetpack enhancing items so you can move around a little better, and find even more chests or secrets.
Farm warp crystals and get all of the warp discs
Warp discs open up new Easter eggs and are even linked to an achievement activity: so buying them and using them is a key part of the endgame. Use this as an opportunity to spend all of the warp crystals you have lying around to unlock every missed sidequest and zone: like Cutie Town or the skate park.
Clear out some achievements and sidequests
There are several sidequests that you can clear out, which range from a general level of unimportance to achievement-locked activities. Although several of them can be missed, many of them can be completed in the postgame.
Here’s a short list, complete with links to guides:
You can also opt to just hang out and watch TV in your house, where several feature films and shorts will play out. If you don’t like what’s on TV, you can step into the bounty machine portal next to the couch and reset it.
Get the secret ending
While this might not be the last thing you’ll do, it could be the most significant of all of these options.
We’ll keep things spoiler free in this article, but we have a full secret ending guide here. Sadly, High on Life does not have a New Game+ mode at launch.