Good start. But, shortly after starting the game, I had a Kiku which died, then the menu allows me to select Stika, which then says 'You switch your Pulpmon for to Kiku' and then repeats the same menu listing Stika. So, got stuck in that loop with no way out before I even saved the game.
A couple of other smaller things I noticed:
The menu is on the A button. Why not put the options into the Playdate menu and then have the A button available for other things?
PulpDex can't be navigated with the D-pad, it should ideally work with both crank and D-pad (much like the Playdate's text input).
When you open the Pulpmon menu item, the selection arrow appears next to both Pulpmons until you move it.
B button doesn't close the menu (though would also be fixed by using the Playdate's menu).
Unable to change order of Pulpmon.
Leveling Pulpmon doesn't appear to do anything yet.