This is really cool! The three bomb system is really interesting and nice to use, story plot is also really fun.

Only minor complains i'd have would be:

+ Shot when power level is even: Whatever sanae is front-facing doesn't get hit since all shots go to the sides (maybe include a default 0 power shot at the center would do?).

+ Isn't 50 a big number to increase power level? (I believe you get one more shot 'option' each level, but feels kinda slow).

+ Diagonal speed is greater than regular directional speed (probably multiplying sqrt of 2 would fix it).

+ Sometimes game loses focus and doesn't come back (maybe it's something of the engine, i don't really know, but would like to).

That's all for now. It's a really impressive and fun game, willing to see more!