Bullet Hell Monday (2016)

The PC release puts clean geometric enemies and coloured patterns ahead of detailed scenery. Chapter mode begins with short, simpler missions, giving you room to recognise a formation before the next kind arrives. Its upgrades also strengthen your craft, so progress there mixes learning with equipment improvement. Move to Challenge when you want to test observation under fixed arcade-style rules: it removes Chapter's missions and levelling, with Easy available. This recommendation is the original game, not the harder Black remix.