Thank you very much for the game. I like almost everything about it. There's ONE issue other than the slow slash: the game maybe too short. The problems about it are:
1. It's a very enjoyable game, so players would want to play a bit more, and the levels are too simple to have replay value;
2. I finished the game, but I'm far from reaching the resource gathering goals (have all swords, all health updates, 999 kupons). Because of nº 1, I don't feel like replaying until I reach those objectives, and because the kupons are painful to gather.
Maybe nº 2 happens because of an unbalanced difficulty progression? I don't know, but I defeated the final boss with the the second sword. Now I have the magical sword and less than 100 kupons to buy the third sword. That was kind of a broken aspect, imo, because final players may not guess the best way to beat the game in as less runs as possible.
Anyway. Congrats for the great work and thanks for sharing here :) It was very fun!