Thank you for your opinion :) Really glad to hear it, as I didn`t have much time to develop this game perfectly :). Yes, i defenitely thought about increasing the difficulty, and yep, my main profile is making games on android, so after the jam I will start polishing this one and making it look and work good on mobile devices. Agree about tutorial, just didn`t have time to draw a few sprites with it, but will add it in final version :)
We had the same issue, ran out of time for tutorial and because of that, many players did not get the chance to play and upgrade our plants :'( . We also plan to develop our game further after the jam and fix all the issues mentioned so far :D
Good luck on your journey, would love to see more from you :D