Should I still post my game? Because I'm nervous that instead of getting constructive criticism I'm going to get roasted to heck and back.

Post it. Ignore the haters. They don't know good game dev when they see it :)

I agree with Divyesh T, your game is yours. You worked for it and everyone should at least respect that and not be mean with their criticism.

Please post it. After working on it for a week you may stop seeing everything that’s good about it. You need that fresh perspective. I feel the same way about mines.

I am late to the party, but please post it! Do it for yourself, you should be proud of finishing something, even if the quality is not great! Take my game as an example,  i start it late and i am doing my art on ms paint just so i can get it released no matter the quality! 

everyone has to start somewhere, and I promise you 99% of game devs’ first game is as shitty as you can possibly imagine.

AS far as I know this community no one is going to roast you for your game as we all come here to learn. And for the jam, the actual goal is to complete your game rather than getting good reviews or ratings. I say you post it regardless of what you think and you will be surprised how great this community is.

You know fortnite? when it started it was the worst game ive ever seen , it had bugs/bad design and more bad things , anyways please submit your game and if you did i promise you i will be the first to play it :)

I honestly feel like the brackeys community is better than that, no one will make fun of you

Everybody starts somewhere bro, post it whatever you got, I’m sure we’ve seen worse :)

You'd be surprised how wholesome this community is. If you don't believe me, just look at the answers preceding mine.

Do it above all for yourself like the others said, but remember that in a marathon like this, merely submitting something we worked hard for (even a very flawed game) is worth celebrating. Come join the party!