Hello DANIEL RAIN,
Thank you for your continuous support! =)
Additional costume is a feedback I received a lot from play testers. However, since I'm not an artist myself, it will be time consuming for me to add additional costumes; a possible alternative solution is to add additional attachable trinkets to the character (perhaps the trinkets could be unlocked by achieving certain mission in the game?).
The idea of character customization is an aspect I haven't put too much thought about it honestly, nevertheless, I'll make sure to post an update if there are news related to character customization in the future.
Thank you again for your advice and have a relaxing weekend. :D