Fun quick little game. I like the idea a lot. I was hoping that I could buy something at some point... but maybe I didn't get far enough. I did really enjoy the selling of the apples animation. 

I think the game could definitely benefit with a little more time to add some other objectives. As it is now, it doesn't feel like anything changes, so the timer just gets closer to what it takes me to pick 15 apples without any variation on my part. I think the selling mechanic could be really fun with a little more time!

That is some hardcore apple pickin' music! 
Your base game concept is pretty fun and I like what has been implemented so far. If you plan to build on it after the jam is over I do have some suggestions! 
Give the player some indication when they collect the apples. I was sitting at 15/15 for a while before I realized anything had happened from me pressing E near trees. 
Maybe increase the amount of apples required for each level or reduce the time? Currently I just didn't see a way to actually lose since I'd have 15 apples in about 10 seconds. 

The store cutscene was a really nice touch. Great job on the game, cheers! 

Nailed the theme.

Some effects for picking up the apples would be nice. And as a major improvement, if you want to continue the work on this game after the jam: Give the player something to buy from his money ;)

The artstyle is pretty solid. Just two tips to improve the art with nearly no work. Delete the bottom black line of your trees, so it looks more like they come out of the ground. Flip some of the trees or if you make several sprites, just delete or add one or too branches. 30min of work and a bunch of tree variants ;)

This is a nice little game for being one of your first ever games!

I recommend trying out varying apple types, and making the money have a little more purpose! Play around with some ways of getting the experience to change slightly to spice up the gameplay. Also don't let the player hold the button down to spam the inputs.

This is a very nice game! Keep it up! :)

Neat little concept maybe would have liked simply no collisions on the trees (or just at the very bass of the stumps) opposed to the awkward way you have to walk past them and the apples just add up. Maybe increase the amount of apples that need to be collected each time and not have a limit but let the player continue to collect apples. A function like, y = a * sqrt(x) + b, where b is the amount for wave 1, a is some sort of multiplier (you could mess around in desmos, https://www.desmos.com/calculator), x is the wave number and y is the number of apples you need. This would just add some more complexity to the game and make it a bit more difficult. Other things you might want to consider for future updates are different maps (like maybe night ex..), some form of NPC that is also collecting apples (where trees they visit can no longer be harvested by the player), and visual cues to say what trees have been harvested (just more visual interactivity in general). Finally if you're looking to make a full release (just my speculation from the comments) maybe consider commissioning a composer to write some custom tracks moving away from the chiptune aesthetic (if you want me to point you in the right direction I'll be happy to help). Overall it's got potential but might need a lot of tweaks to be as good as it can be. 

Cool short game! getting apples and selling them. I think everything was well made, but the jiggling trying to get close to tree (the collision). Overall, awesome job! congrats on your entry.