Ive been using GraphicsGale - a free pixel art program with quiet a few youtube tutorials available online. 
You can download it from here
graphicsgale.com
Saw your post on r/itchio
Here's a play-by-play of all the steps I did.
When I hit 'Play' there was a wall of text. I didn't read though it because the game splash and this screen is designed to look so appealing that I though I'd jump into the game and figure it out. Big Mistake :)
Once I hit the flashing right arrow, the in-game screen had quiet a bit of content to grok. The background text caught my eye, as I started reading though it I noticed the first emoji fall downwards. I was not sure if I had to do anything yet as I was still reading though the text. In a very short moment, a bunch of emojis started falling down. And before I knew it - I hear the buzzing sound. The Emoji Life bar on the top right caught my attention and displayed one crossed out emoji. The screen cleared up for a brief second, before the second set of emojis filled the screen and I lost a second emoji life. The third try came and went really fast and and the 'High Score' screen took over.
I hit the flashing 'replay' icon, hoping to read though the instructions this time around, but was directed back into the game.
So here are my suggestions
1) On the Launch Screen - you can change the text from 'Play' to 'Start'. I do love the flashing button because you have used that consistently though out all the screens and it is attention grabbing.
2) Simplify some of the instructions - may be "Tap on these Bad Emojis" and show three of them below.
"Let only the good emojis through" three examples below this line.
"Hit [Send]" after collecting emojis!".
Add the "Play" button here so player knows that they are now going to start playing the game.
3) Have a counter here so the Player can get ready. (3,2,1...)
This will give them enough time to study the UI and figure out what's on the top right, and bottom of the screen.
4) For the first x (where x is any number you decide) emojis appear at a slower interval, and move slowly towards the bottom of the screen.
5) There should be sound auditory or visual feedback when you tap on a bad emoji and destroy the object. There should also be some auditory or visual feedback for all the good emojis that get collected in the message box.
6) The first time you collect three good emojis, give the Player a little more time (either increase the interval rate at which new emojis are created, or reduce the speed at which emojis fall)
7) If you really want to teach the send mechanics, have three good emojis fall first, once the three emojis enter the message field, flash the 'Send' button so players figure out that mechanic. Then slowly generate a few good emojis and an occasional bad emoji for them to understand the mechanics a bit more.
8) Id suggest moving the "Score" and emoji lives to the lower section of the screen so it does not create too much visual clutter towards the top of the screen where emojis populate at birth.
Alternatively, you can use a opaque header behind the UI to visually separate the UI from the in-game emojis.
9) When a bad emoji hits the message box - the message box has the X mark on it, and so does the life - both happen at the same time and both are attention grabbing. Which one do you want your player to focus on more? Make sure that element is blinking only.
10) Make it less punishing where the player does not lose all their good emojis collected in the message box. After all they are losing a life.
11) I am not sure if there is a victory screen, but I did see the High Score screen a lot :P . I wish there was a button to the instructions here, just in case one needs a refresher.
12) Credits screen has a lot of links - none of them clickable. I wonder if that is because of my adblocker plugin or it was not programmed to be clickable. The Menu button is a bit buggy too. I had to refresh the game to get this playing again. 
2 days left!
I got the Dialog system working but the 9 sliced object does not behave like a regular object. Even Pinning that object does not work for strange reasons.
Pretty sure this has to do with pinning objects and Game Object Behavior.
On a completely different note - there's just a day or two more remaining on this gamejam and Im happy I got to learn how to even build a game in Construct 3. I appreciate all the help from the construct forums and the itch forums. I will continue working on this project and moved the dev blog over to http://devilsworkshop.tumblr.com/
So to reevaluate I am so happy I got to learn the following things
Thanks for staying tuned and congrats to the folks who have finished their game! Hat's off to the organizers of this fun gamejam! If it weren't for you guys I would have not explored making solo games as an option - cheers!
5 Days left
Update 1 and Only 1
It's been a very frustrating experience trying to tackle Z Order sorting in Construct 3. There are not too many tutorials that explain the logic behind how C3 handles this. One kind soul from the forums helped me with the code and I have a ton of appreciation for them sharing their code. Read more about it and grab the source file from here.
But my next steps are to get a good understanding behind the logic of Z Order / Families / and Instances.
For now, here is the finished scene for today's update
Day 6 and counting down.
Update 1
I've hit a wall with Z Order sorting. Dang
From my finding - it is easy if the Layout has a player and one object to Z Order Sort
When introducing a second object to Z Order sort - the game behaves strangely and only sorts one of the two objects
To the interwebs! Hopefully I get an answer soon
Day 7 and counting down.
Update 3
Documenting some of the mistrials of learning Z Order Sorting in Construct3. In this case I have figured out rudimentary Z Order sorting between player and one object. The big challenge is applying Z Order sorting to an entire family of objects and building the events efficiently so that the game does not drop frame-rates
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Let’s consider three objects
For the first part of this exercise, lets focus on the player and the door.
The player has been assigned some basic controllers.
The Z Order Bar looks like this
If you run the game now, the player will move behind the Door and RandomProp
Now we are going to do a conditional check.
Create a condition - where if the players pivot point.Y is greater than the door pivotpoint.Y -then resort the Z Order of the door and move it behind the player.
Quickly testing that condition we get the following results
Ok, so it works. Initially the game checks the zorder for the three objects - the player is behind everything - so when the player moves it goes behind the door.
Now when the player moves downwards, the player pivotpoint.Y is greater than the door’s pivotpoint.Y - so the system immediately sorts the player to the top.
And when the player goes back to the top where it’s pivotpoint.Y is lesser than the door’s pivotpoint.Y - we have not assigned any condition so the player still stays Z Order sorted to the top and goes over the door.
Let’s add another condition to instruct the system to check for Z Order sorting between Player and Door and display it correctly
Small update to the event sheet. Instead of moving the Door in front or behind the Player, that has been changed to the Player now moves in front or behind the Door. I anticipate there will be many objects that have to perform the same function and this method already feels inefficient.
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When the condition exists for two objects - the system does not perform the expected behavior and the Door's sort does not work while the RandomProp's sort order works.
I will need to research 'Sort Z Order' a bit more as the concept is new and a bit confusing
Day 7 and counting down.
Update 2
Things to remember the next time I am working on a Construct3 Project - Organize everything so it makes sense.
Took a pass at standardizing all the layers, and Project folders and objects. I also made a template Layout with the same Layer names so I can easily create the next layout with ease.
Though this took me quiet a bit more time than anticipated, Im glad that this helped define future project pipelines using Construct3
Day 7 and counting down.
Update 1
Updated 5 - Last one for the night
