That core loop is simple: run around the island of Ditto defeating enemies to level up, collect the “Toys of Legend” to get new abilities and powers, weaken the main bad guy (Mormo) by completing certain objectives, and then confront and (hopefully) defeat her. Excepting the final boss battle, you're only given a certain number of days to do everything, which varies based on your chosen difficulty (six on Easy, three on Medium, and two on Hard). You can temporarily extend that limit (eventually), and time stops altogether when you’re in the main town and in dungeons, but inevitably you’ll confront Mormo.
The final battle is easier if you’ve spent some of that limited time defeating monsters and gaining levels. Every time you level up, your health increases and you unlock slots on your hero where you can apply “Stickers” to boost stats. These Stickers are special items that you either find in chests or purchase from vendors. There are a variety of Stickers to find, but their main benefit is to increase various stats, like attack power, defense, and elemental resists, though a few also add new abilities (like a spin attack) to your repertoire.
Whether you win or lose - and dying at any point in your adventure counts as losing - you’ll start the loop all over again 100 years later as a new protagonist with only your experience level, a couple basic toys, and whatever gold you collected in your previous life (along with another unlockable currency) to your name. Not quite square one, but not too far off. In keeping with the “rogue-lite” shorthand, too, the world itself is randomized. Dungeons, key landmarks, and certain vendors are no longer in the same locations, and the layout and contents of dungeons have changed, too.
While the core gameplay loop is fairly solid and fun, there are a number of small issues that crop up. More than once, I found myself wishing for more fast travel points so I could get to certain areas faster and not waste time moving through the world. Until you discover/acquire certain Toys of Legend, bombs are the only way you can blow open cracked walls in dungeons (something that becomes necessary later on) and your bombs are in very limited supply until you discover a certain NPC. Certain enemies can be difficult to deal with unless you have some specific Toys of Legends, and while that makes for an interesting challenge your first couple encounters, I ended up blowing past them later on unless I had the right tools to deal with them. When you successfully defeat Mormo, you have to repeat the same sequence of intro events (get woken up in your room, go retrieve the sword, go talk to Mormo, go to talk to the people in the town) every single time. The first or second time, fine. The third, fourth, fifth, or sixth? Please let me skip this.
The bigger problem with all of these is that they are not issues you encounter once or twice and move on. You’ll run into these - or your own list of personal gripes - every time you play, and you’ll have to play a lot if you want to figure out what exactly is going on in The Swords of Ditto. Therein lies the game’s biggest problem.