Firstly, what a fantastic achievement for a first game, and under a month of rolling your face on the keyboard. This is a cracking game all things considered. So, first things first, my high score:
I definitely enjoyed this, it's very simple, but addictive. I think it's the multiplier that really gamifies the scoring. I'm fairly certain that if it was just a linear +1 to the score for every jump, it wouldn't have held my interest for nearly as long.
I do agree with some of the others that it might not be obvious what to do without reading the description. I did, so thankfully there were no issues, but it's rarely a guarantee that a player will read it, so it's good to show the same information in-game.
I thought the difficulty ramped up really nicely, I did try to find a safe spot to cheese the score, but I couldn't, so kudos there :D. It would have been lovely to perhaps have a small window showing the score for that run before it resets so that one can sit and bask in their successes when getting a high score. Perhaps even a high score label too! However, I'm well aware I'm asking a lot and expecting far too much of you for a first game and a first jam. What's here is excellent and perhaps these might be things to consider for the next one.
I think I only encountered a couple of bugs that were very very minor. The Modifier label occasionally displayed 'N/A' and if jumping while touching a wall and turning into it, the Flamingo sometimes stutters. These are super minor and I'm really only mentioning them for completeness and they certainly aren't something that affect my opinion or scoring.
The art is lovely, I especially like the flapping animation; did you also draw these yourself?
All in all, this is an impressive first game. I hope you're proud of yourself, and I also hope my feedback doesn't come across as picking holes.
Great job, I had a lot of fun