I like the idea: it's Plants vs Zombies, but with new two-sided gameplay. The descriptions of cards help a lot: for example, under the tulip it's stated that it's most balanced option - and it really helps to play the game and start getting progres.
Another thing i like is the variety of plants.
About the suns resource - because i was always low on money, i had only a few cards and suns are nearly never exceeded (therefor the meta for me was to buy tulips and no sunflowers).
The art style gives Undertale vibes.
Good progres!) It would be nice to see you on other upcoming jams!