Here is the list of the broken promises since the Umbra was announced on Kickstarter:
1.) They promised early access (alpha+beta) to both Windows and Linux users. Linux users didn't get early access.

2.) They implemented rotating camera feature in alpha. They romoved the camera rotation with the beta announcement.

3.) In April 2018 they announced official beta release for both Steam and Gog users for late September. The following happened:
a) Beta release was delayed for October.
b) It turned out not to be the full beta release. They split it in early beta stress test scheduled for 5th of October, and beta content test for 12th of October.
c) Beta stress test and beta content test got delayed again.
d) Gog users were excluded since the official announcement of the beta stress test and beta content test phases.

4.) They promised they would listen to community, and their feedback. They banned some users in Steam forum instead, who complained about constant delays and broken promises. Users were worried about the delays, the competition the game will have to face and potential financial issues the studio could face. Some threads and comments got locked and/or deleted, as they obviously can not stand constructive negative criticism. Some users were banned for being toxic, other were not, but simply critical of the developer.

5.) They promised classless builds in Kickstarter.
a) With the introduction of the catalyst off-hand items, melee hybrids will not be able to use umbra spells if they do not hold an off-hand catalyst item. That will make melee hybrids with shields impossible to build. Melee fighters using two-handed weapons will not be able to wield two-handed weapons and cast umbra spells. Dual-wield melee fighters will not be able to cast umbra spells.
b) Archers will not be able to cast umbra spells, because they can not use off-hand items while using bows.
c) Mages will not be able to use rage spells, as rage spells now require melee and ranged (crossbows, pistols and bows) weapons.