Thank you :-)
Yes, that was really the point actually. The more difficult it is, the faster people would probably stop and/or the more of a hint-system would be necessary (for what i unfortunately had absolutely no time anymore^^). So like you said, aiming for 1 or 2 "game-overs" before you actually finish it (what results in ca. 5-15 minutes play-time) is probably best for a game-jam when people want also to play lots of other games.
Good idea, that i actually just could have added controllers additionally. Not even thought about that to be honest, for me it was just a this or that decision^^