Broadly speaking, problems A-B-C-D were "div2 problems", while F-G-H were "strong grandmaster problems" (with E staying in the middle). I did not expect anyone to solve all the problems and thus I decided to give the scoring F+G=H (so that maybe someone would have solved H).
Many of the problems (A, C, D, E, G) admit multiple solutions. Sometimes the core of the solution is the same (C, D) and sometimes the solutions are truly different (A, E, G).
If you are an experienced participant, I would like to hear your opinion on the problems. Feel free to comment on this post or send me a private message.
Problems F, G have a similar difficulty. They are very different, so participants could choose which one to attack depending on their taste. Problem F-Boring Card Game asks to reconstruct the moves of a game given the final situation. Even if it looks as one more constructive problem, it is not. The crux of the problem is finding a criterion for the admissibility of a final situation and then noticing that a naive greedy algorithm produces a sequence of moves generating such final situation. It requires quite a bit of thinking, but then the implementation is trivial. Problem G-One Billion Shades of Grey has the clear smell of a flow, and indeed it is a flow problem! There are two possible approaches: either you have a clever idea, or you apply some advanced classical theory followed by a certain amount of optimizations. Compared to problem F, in G the ideas are more standard but the implementation is not immediate. Since the statement is extremely simple, it is possible that some versions of this problem are known (and I actually found at least one research paper considering something similar). I decided that the problem is beautiful enough to take the risk.
Finally we have H-Prison Break which is much harder than all other problems. Even if it is a variation over the well known Cat and Mouse problem, knowing the solution to the latter is not very helpful. It is a very nonstandard problem and a mix of mathematical insight and ability to handle an involved implementation is necessary to get accepted.