It's an actual game at this point lol. Press Z to select buttons, arrow keys to scroll, Space for Help andddd yeah. If your HP goes down all the way you die, attack enough and you win. Also idk how but I messed up the defend button slightly, you have to go to PSI first then press right to get to it lol. Also about 30 seconds in a button will appear that you can click to recover PSI, however it only shows once and for a couple seconds.
Images all from Earthbound. Thanks to Ninty lol