There is two major point i found frustrating:
1) Sometimes enemies spawn right besides you. Reasonably sized no spawn zone around the player would be welcome.
2) There is very noticeable input delay with changing walking direction, as a result despite pressing the correct direction I've dodged into the mines multiple times.
Played only the browser version, so maybe it's web fault.
Otherwise the game is promising and with very pleasant art style. Good job!