I liked this take on the theme so 5 stars there! I've never played as a flea before lol, and I just found it really novel that instead of collecting coins (typical of 2D platformers) that I'm collecting blood instead. I thought that the overall mechanic was really good too - the way your jump height is affected by how much blood you have, and how you basically cant jump without blood - especially when jumping is your only way of moving (typical of being a flea) -its really interesting and quite novel (I've never seen this mechanic in a game before). I cant decide if its too hard or not - I cant decide if it would be a good idea or not to have a power bar for your jump, or similar. I think the answer to that will depend on your target audience! This is a great kind of 'rage' game just as it is. It's the sort of game that you cant really master with one play. You have to play it multiple times to get the 'feeling' for the jump mechanic. Overall I'm a big fan of this so great work.