Cool idea; I would have liked to have seen more mechanics, as you mention in the description. It feels like there could be interesting things you can do; e.g. have a legit pokemon-esque battle system where you level and eventually go destroy the town or something.
I tried my best to find pro strats, but I could never make it past Day 4. It was quite difficult to understand where the trainers are walking; having a lerped movement rather than just an instant move might have been helpful in making their patterns a bit more understandable.
Oh, and there was a level that went up as you encountered trainers; is that just cosmetic? I couldn't figure out what it did, if anything.
Also, I loved the swarms of trainers running around aimlessly for this one grassmon.