Update 0.89 Alpha

Changes: Code optimization, improved performance ( working on further improvements ). Several changes to enemy waves. Many bugs have been fixed. [img]https://steamcdn-a.akamaihd.net/steamcommunity/public/images/clans/31941173/345e2ad2bb5c2d5354a1a2313d09d71eeaf03894.png[/img] [img]https://steamcdn-a.akamaihd.net/steamcommunity/public/images/clans/31941173/4650e06e89c3fa388d97fd958c9af48c136ac98b.png[/img] [img]https://steamcdn-a.akamaihd.net/steamcommunity/public/images/clans/31941173/449d872a07473515516ed925437a9012a5730fb3.png[/img]