As someone who has spent a lot MORE than 15 minutes (100-200 hours) I can say you will get out of Risk of Rain 2 what you put into it. It's a "Rogue Lite" game where the more you play the more shit you unlock for future runs.
This plethora of unlocks includes
1. New items to be in the pool
2. New characters as well as new move sets for all characters
3. Higher difficulties to test your capabilities as well as leading to new unlockable shit such as skins
4. Artifacts that SIGNIFICANTLY alter the way you will interact with a run. (Want to be able to control your item build? Discover the Artifact of Command and you can CHOOSE what items you unlock in every chest, etc)
This game also has a very active mod scene as well.
Want to play as Goku or Vegeta? Got a mod for that, as well as a shitload of other new characters to mod in and play
Don't like the way certain movesets interact on some characters? There is probably a mod for that too
DO YOU WANT YOUR FEMALE SURVIVOR RUNS TO HAVE DUMPTRUCK ASSES? WE GOT THE MOD FOR YOU.
So yeah don't just write off Risk of Rain 2. It's pretty good if you are into the rogue lite genre.