That could be a bit tricky, hehehe.
Right now, it’s possible to start the game without selecting a difficulty, which means enemies aren’t triggered. This way, I gathered all the resources, removed all the mining stations, and built the cannons before any attacks. It saved me CPU time, and I was able to reach the top of the leaderboard without too much trouble.
Speaking of the leaderboard… I imagine this structure is limited to the prototype, but I have to mention it: if a leaderboard is part of the final version, I think it is wise to consider a fixed amount of resources for the map or difficulty level. At the moment, it’s variable, and that can affect individual results. Anyone lucky enough to get fat asteroids will definitely have an advantage.