Hi, first of all thank you for your kind message and your very useful feedback!
I'll be honest, I never thought about that problem. While I do have many ideas for the bosses, I must admit the way you fight them is indeed similar to the ones you fight in the Super Smash Bros. series, or the Shovel Knight bosses, to give another example.
It's actually a very good advice, and while the first boss is already done for the next demo (and I currently don't have the time to remake it), I'll definitely consider the question as I now think of many new possibilities. A huge, huge thank you for that.
I sincerely hope you'll enjoy what's coming next!