Great game, well implemented risk mechanic! At first I didn't understanded what was going on, but after retrying I got the idea which was very fun, I liked that the risk mechanic was random, you always got a 50/50 chance, which made me decide what exactly I was willing to lose in case luck wasn't in my favour :)
Just one suggestion I would make is decrease a little bit the hitboxes and make it so the player can heal in any form that doesn't require upgrading health.