I'm happy you enjoyed it! In the past game jams I've joined, I've had experience with my players skipping the instructions or the tutorial, so I thought just placing the tips in the game itself would be better :)
Yes, those stealth kills are pretty hard to get perfect in! After this game jam is over, I'll try to put an online leaderboard so people could fight for the best time, best stealth kill percentage, and more :)