After some retries I reached the endless part and eventually killed 326 crystals.
The different upgrades makes it fun to replay, unless it went super well it's likely you did not get all the package during your very first run(s) and as you're getting the game it's also cool to try and choose the upgrades in an order which seems appropriate.
The game is cool. The art is clean and the controls, feedbacks, speed of everything, stage progression, upgrade progression and difficulty all feels on point, and as a result the game feels well rounded and is very pleasant to play.
Thanks for sharing.