Game management and lack of experience was definitely a factor.They completely outplayed Croatia in the first half but didn't put the ball in the back of the net. Kane missed two sitters in about two seconds! Then they collapsed in the second half. Might be fitness levels and stamina or lack of game management or experience - or a combination?
I didn't think England reacted very well to conceding an equaliser either in this game or against Colombia.
I will caveat this by stating that I only saw the second half of both the Colombia and Croatia games and didn't see the Sweden game, but I thought Harry Kane was really poor in the games I did see.