HyperSonic - Feedback & Strategy

Contests
19

Rank 6. My first contest at CG, the experience was amazing. Standing at rank 1 a few times for some 20+ cumulative hours was a huge thrill. :smiley:

Game feedback

  • The game itself is great. The complexity was balanced just right, and had enough room to elaborate different strategies.
  • The bizarre ordering of actions in each turn caused a lot of unnecessary frustration and bugs. “Half-destroyed” boxes you can’t walk through, getting your bombs one turn after explosion, the input not giving the real/full state of the game, etc.
  • I wish there were different wall combinations and a smaller amount of items overall, it could have added more interesting depth to the game.
  • The endgame was boring and a waste of 100+ rounds. It should have ended as soon as the last box is destroyed. That could have given us MUCH faster IDE and submit results.
  • Seconding Magus on the 50ms per turn to help on the same issue, and maybe favor more strategy over computing power.
  • The server issues on the last day or two were a nightmare. I wasted a lot of time (8+ hours) with servers timing out for over 9 games out of 10 at times.

My strategy

I only summarize the final version to keep it short. I might write a blog with the full story and more details later.

  • I used a variation of GOAP (goal oriented action planning) with A*, which on average planned ahead the next 20-25 rounds.
  • To further explain, instead of evaluating the set of immediate possible moves (directions and/or dropping a bomb), I would instead define medium term actions: pick up this item, bomb this (set of) boxes, wait for an explosion to be over, etc.
  • The cost function is the number of turns elapsed after the current one.
  • The heuristic function is the negated cumulative score of each action taken. For example, bombing boxes had the biggest score, small bonus for boxes destroying earlier or if the box contains an item, another bonus for picking up an item, etc.
  • I later added a voronoi diagram to favor areas I can reach faster than enemies and penalize the other way around. It helped keeping my bot safer, and not waste time considering boxes the enemy will probably get first anyway.
  • Towards the end, I added a leash algorithm to check the possible bombs the enemy could place in the next 3 turns and determine if a (suicidal) move I make this turn could lead me to a mostly guaranteed death. Sadly, the final version still had a few bugs, and the long site/server issues did not help testing it as much as I would have wanted to.
  • The leash pass would be executed first and then, when planning, would yank out the action nodes starting with the suicidal moves.

Other notes

  • I wasted a lot of time trying to make a fast and reliable heuristic to evaluate traps and danger zones, when in the end, the leash ended up just better overall, even with the bugs.
  • It turns out I was actually losing a lot more to poor score than death. Focusing that much on preventing death was similar to optimizing a function that’s actually taking 5% of the running time — probably not worth it when you can optimize the other 95% instead. Doing it again, I would have spent more time improving the scoring and planning heuristic instead.
  • Against my better judgement I did not take the time to write functional tests. I paid for it several times, debugging stuff after refactoring that could have been easily prevented.
  • Magus’ stats website was a tremendously helpful tool to figure out which opponents/game modes to focus on next. I hope CG will provide stats like this in future games, with more metrics like timeouts, deaths, score differential, etc.
  • The timing of The Accountant contest was very poor. I understand the marketing reasons behind it, and if it helps CG get more money it’s for the best, but it still sucked to see the attention turned away from the current contest towards the end.

Thanks to CG for the awesome contest and to the participants for providing an incredible challenge, kudos to Ixanezis and Romka who ended the contest in such a dominating fashion. I am eager to participate in the next multiplayer contest. :slight_smile:

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