Incredible job!
A great level of polish and a fun concept. The idea of choosing your companion and the one you don't choose becomes an enemy is really fun and unique!
Only negative feedback is, in it's current state, I level up so often that with the timer pausing when I level up, reading the 3 cards, it took me about 10 minutes to get through 5 minutes on the timer. It might be worth reducing that 15 minute goal so people are more likely to play to the end.
Amazing work! Loved it!