As mentioned by others, the art, sound, control are all quite nice, but the system as a whole isn't really fun.
So far it's easier to survive by buffing up planting cool down as much as possible and try to mass farm silvers and thus use silvers only. What's the purpose of all the bullet variety? I didn't even fire 1 gold before day 7, the day where it begins as endless mode, let alone the infinite but weak beans. You just might manage if you switch between planting gold and bean bullets once in a while, but this only makes the game more difficult and most of the time your pig will die.
Let's not forget the way the seed lands. Since you can't make your pig jump, where it lands matters a lot, as once your pig is surrounded, if you're running low on ammo you're screwed. But not only is planting at a specific spot very unintuitive(you need to fire upwards), any following seed when rolled against it will change it's location.
Also, every bullet have nontrivial recoil, if it's weak, the recoil is small, but you need many shots, if it's strong you only need 1 or 2 shots but the recoil push you very far away, so in the end, the net is about the same and you'll be busy adjusting either your own or your pig's position most of the time.
These kind of micro management is very annoying.
I will to say the hit/explosion effects are superb. They have a megaman feel to it. But a game wouldn't mean much if it's not fun. Fix that and you have a decent arcade style game.