This may genuinely be the most beautiful game I've ever played in my entire life, calculator or otherwise. The words "Happy" and "Calc" do not sufficiently describe the joy one feels whilst playing, nor do any other words in the English language.
The controls are fantastic and so intuitive. The score saving system is really efficient and innovative. I don't know how you managed to only use half of a bit to store save states. The 120 fps graphics are also unbelievable, and I'm still amazed by the built-in overclocking feature.
I think you could've done a little better with the beta online multiplayer feature, but it's still fun. The local multiplayer with USB controller support works a lot better.
The plot & dialogue brought me to tears, and some of those cutscenes deserve an Oscar. I'll try not to spoil anything, but it's so emotional on level 43897 when you find out your brother was the villain the whole time.
The only thing wrong with it is the rollover error on level 65536. It would be nice if you added more levels since it only took a few months for me to beat it.
Overall, 10/10.

sadly didnt work on my calculator, great game nonetheless!

My review of HappyCalc:

Originality: 10/10 Very innovative
Gameplay: 10/10 Outstanding
Graphics: 6/10 No ray tracing, no path tracing, no 3D lighting or shading effect, no 4K resolution, not even 240 frames per second.
Replay value: 10/10 Fun to share with fiends.

Verdict: 9/10 Very cool game but any calc game needs 3D ray tracing and 4K graphics.

exquisite and entertaining - truly a high quality masterpiece of a game.

this is defently teh best epic game of all time try it is 100000/10 i love this gamee i so coool amazing sause cool #pleasegetthisviralnoworiwillcometoyurhousrandbreakurtoes

Nice game!

I love this!

This program cured my depression. My friends are bursting into joy just playing the game.

Edit: My friends are still laughing on the ground, but they are also spitting. How rude.

great game id recommend it to anyone

Wonderful game, I'd recommend this to anyone who has just gotten a CE or is planning to get one. Beautiful.

How did you get it to run? I’ve tried to do stuff like that, but it never works for me. 10/10 I hope to see more amazing games like this in the future!

best game ever

This program is pretty good.

Back up your files before using this!!!

This program is incredible, probably one of the best games you can get for the CE calculator.

This program is GREAT. I laughed so hard because I was looking for a new game to play and found this! LMAO this program is awesome and definitely recommend to anyone who is looking for a new game to play on the CE.

What an amazing game, extremely replayable and very fun! 9/10 Graphics 10/10 Replayability 9.5/10 Gameplay :)

Got in trouble because I was laughing so hard, 10/10 would laugh again. EDIT: Unfortunately, this program has not been updated to utilize the latest C libraries. Therefor it's a pain to run nowadays since you need a library that no longer exists. Here is a direct download link to compatible C libraries: https://github.com/CE-Programming/libraries/releases/download/v6.5/clibraries.zip

Ha Ha! This is awesome! I love it!