+ lets me find my own way to beat it -> I feel clever (Although I suspect the authors did not intend this but left holes in their game design instead)
+ lets me shoot my own bullet hell (But see below!)
+ very effective character stats system (Health, damage, range, etc. - all have direct influence. No overhead-layer with "strength, dexterity, endurance,...")
+ the music
+ not too easy and enough health points to not be too frustrating (your mileage my vary)
- NO expanding dungeon! (Did normal mode in ONE DAY) You only get: 4 acts. Each has: 4 maps + 1 boss map.
- Procedurally generated? Big words for merely swapping around the same rooms.
- very limited monster variety
- boring level graphics - although that's the smallest of the problems for me.
- broken ammunition / weapon design
The ammunition rules in this game effectively kill most of the fun you could have had with the advertised weapon system:
- Die in normal mode: lose all weapons !
- Empty your ammo -> lose your current weapon !
- Ammunition *as loot* drops only in ineffective doses
It is not easy to maintan armor repair costs with the loot money. But ammunition cost?! Even if I dedicate all my money to ammunition...
- I can only buy ammo in town
- I can only go to town before starting the next map
- I can only fill up the (250 shot) magazine of the weapon.
Effectively I had to use the boring one-shot default weapon most of the time because it has unlimited ammo. And only use the cool weapons sparingly. Switching these weapons on and off was an additional annoyance. (HOTKEY?!) Did I mention you lose ALL weapons when you die? I feel betrayed by the ads promising me to shoot one gorgeous pixel wave after another.
The game design also has other very rough edges. Example: Shooting the containers standing around all over the maps takes multiple shots on most containers. So I stood and fired and waited until they broke - this filled at least 25% of all time I played this game. Very annoying. Although I carried neither armor nor upgraded weapon for a long time to save money, I still needed the money from many of the containers. So why not let all of the containers break on first bullet? It would then turn around the experience and be fun instead - to see all the environment break under my bullets fast and easy. (By the way: More damage does NOT make them break faster. In later levels you even get containers that need MORE shots. FACEPALM! I suspect very short sighted game design here: "These containers look more robust, so I decide they break after 4 shots instead of 3.")
All that said - I DO like the game.
But I made it my mission to warn you and tell the truth - which the ads DO NOT.